The interpretation timeline
1 Timothy 4:15 Douay-Rheims

Meditate upon these things, be wholly in these things: that thy profiting may be manifest to all.

A.D. 220 – 1871 6 witnesses

Patristic

before A.D. 750
220
A.D.
Tertullian Patristic
c. A.D. 150–220
“If he is making prayer to the Lord, he is near heaven. If he is bending over the Scriptures, he is "wholly in them." If he is singing a psalm, he satisfies himself.”
407
A.D.
John Chrysostom Patristic
A.D. 347–407
“"Meditate upon these things; give thyself wholly to them." Observe how often he gives him counsel concerning the same things, thus showing that a teacher ought above all things to be attentive to these points. "That thy profiting may appear," he says, "to all." Thus he would have him appear great and admirable in this respect also, showing that this was still necessary for him, for he wished that his "profiting should appear" not only in his life, but in the word of doctrine.”
Source

Scholastic

c. 1100 – 1500
1273
A.D.
Thomas Aquinas Catholic
1225–1274
“Above, the Apostle exhorted Timothy to piety; here he gives him the form of teaching piety. In this he first enjoins him to teach piety; second, how he may be fit to teach, at "let no man"; third, how he should teach different people differently, at "the elder." Now the teaching of piety consists in two things, namely in things to be done and things to be believed. But as to things to be done, those who have authority ought not only to instruct, but also to command. And therefore he says, "command these things." Titus 2:15: "rebuke with all authority." As to things to be believed he says, "and teach." Matthew, last chapter: "teach all nations." Job 4:3: "behold, you have taught many." Then when he says "let no man," he shows how he can be fit for the aforesaid things, and first for commanding; second, how for teaching, at "till I come." Concerning the first he does two things, because first he teaches how he ought to exclude contempt; second he shows by what it is to be excluded, at "but be an example." A command has no efficacy except through the authority of the one commanding, and therefore when authority is despised, the command is frustrated, which happens most of all in youth, because such persons are not believed to be prudent. Hence, according to the Philosopher, no one chooses the young as leaders. And therefore he says "let no man," etc., as if to say: although you are young, let your character nonetheless represent old age. Tobit 1:4: "when he was younger." Then he shows how contempt is excluded, saying "but be," etc., namely that you show yourself such that you may be an example of doing what you teach by word. And it should be noted that in those things in which a prelate is an example, there is a manifold difference. For some are ordered toward one's neighbor, some toward God, some toward oneself. As to one's neighbor he says, "be an example of the faithful," namely that what you command by word, you fulfill by deed. 1 Peter, last chapter, 3: "made a pattern of the flock," etc. And this in speech; hence he says "in word," namely, weighed, ordered, and circumspect. Colossians 4:6: "let your speech be always seasoned with the salt of grace." 1 Peter 4:11: "if any man speak, as the words of God." Likewise in outward conduct, that as he excels in place and dignity, so also in honest conduct. 1 Peter 2:12: "having your conduct good among the Gentiles," etc. Matthew 5:16: "let them see your good works, and glorify your Father who is in heaven." As to God, it is ordered by charity, which perfects the affection; hence he says "in charity." 1 Corinthians 13:1: "if I speak with the tongues of men," etc. Colossians 3:14: "above all things having charity." Likewise through faith, which illumines the intellect; hence he says "in faith." Hebrews 11:6: "without faith it is impossible to please God." Which especially befits prelates, who are the guardians of the faith. Hence in Luke 22:32 the Lord especially prays for the faith of Peter, saying: "I have prayed for you, Peter, that your faith may not fail." As to himself, chastity orders life and mind, because it is exceedingly unbecoming that the life of the ministers should disagree with the life of the Lord. Ecclesiasticus 10:2: "as the judge of the people is, so also are his ministers." But Christ so loved chastity that he willed to be born of a virgin, and he himself kept it; therefore there follows "in chastity." Then when he says "till I come," etc., he shows how one may be fit to teach, and first he does this; second he assigns the reason for the aforesaid admonition, at "do not neglect." Now one is fit to teach through two things, namely through reading, in which he acquires knowledge, and through practice, in which he is made ready. And therefore he says, "till I come, attend to reading," namely of the holy books. 1 Maccabees 12:9: "having for our comfort the holy books." John 5:39: "search the Scriptures." And this is signified in Exodus 25:12ff, where it is said that in the ark of the Lord the staves should always be in the rings, and the rings in the corners: as if always ready to be carried. But for practice, exhortation is necessary on our part as to things to be done, doctrine as to things to be known. Therefore he adds, "to exhortation and to doctrine." Jeremiah 3:15: "I will give you pastors according to my own heart, and they shall feed you with knowledge and doctrine." Then when he says "do not," he sets forth the reason for the aforesaid admonition; and first he sets forth the cause from the gift received; second, the cause from the reward expected, at "take heed to yourself." Likewise, first he sets forth the reason; second he shows how what is contained in the reason can be fulfilled, at "meditate upon these things." He says therefore "do not," etc.; as if to say: rather attend, because he who receives grace ought not to be negligent in it, but ought to bear fruit from it. The servant who hides money in the earth is punished on account of negligence. Matthew 25:24ff. "Do not, therefore, neglect the grace," etc. By this understand either the episcopal dignity, or the gift of knowledge, or of prophecy, or of miracles, none of which ought to be neglected. 2 Corinthians 6:1: "that you receive not the grace of God in vain." I say the grace "which was given you by prophecy," that is, by divine inspiration. For in the primitive Church, where elections were made purely and for God's sake, no one was assumed into the episcopate except through divine election, just as Ambrose and Nicholas were elected. And this inspiration he here calls prophecy. Hence the Gloss says, that is, through the election of the saints, because the saints did not elect one whom they did not know to have been elected by God. Likewise the Apostle foresaw that this one would be profitable to the people. Proverbs 29:18: "when prophecy shall fail," that is, such a manner of election, "the people shall be scattered." And how? "With the imposition of the hand of the priest." Another text has "of the hands of the presbytery." And, as has been said, the names "presbyter" and "bishop" are interchangeable, because it was priests and presbyters, that is, bishops, who were received with the imposition of the hand. Numbers 27:18: "call Joshua, and lay your hand upon him," etc. The Lord also laid his hand on the children, as is said in Matthew 19:15. Likewise the apostles on the seven deacons, Acts 6:6. And therefore hands are laid upon those to be ordained bishop. But the question is, since a bishop ought to be ordained by three, why is it here said "of the priest" in the singular number? I answer: he says this because although many come together, nevertheless one is the principal and the others are co-assistants. Yet it can be said that at that time this constitution did not yet exist, and then there were few bishops, who could not be gathered together. Another text has "of the presbytery," that is, of those who laid hands upon him, not insofar as they were men, but insofar as they were presbyters. And this imposition signifies the conferral of grace, not that the ministers give grace, but that they signify the grace given by Christ. Hence it belongs only to those who are ministers of Christ. And therefore he says "of the presbytery," or "of the priest," because the imposition of hands is one thing when done by deacons, and another when done by presbyters. Then when he says "meditate upon these things," he shows how what has been said may be fulfilled, namely that he should continually meditate on those things which pertain to his office. Hebrews, last chapter: "for they watch as being to render an account for your souls." "Meditate upon these things," therefore, that is, frequently consider, the things that pertain to the care of your flock. "Be in these things," that is, let your whole strength be directed to this. And why? "That your progress may be manifest to all." Matthew 5:15: "no man lights a lamp and puts it in a hidden place," etc. Philippians 4:5: "let your modesty be known to all men." And these things he ought to observe on account of the reward expected, on account of which he adds, saying, "take heed to yourself and to doctrine." Some so attend to doctrine that they neglect care of themselves; but the Apostle says that he should first attend to himself, and afterward to doctrine. Ecclesiasticus 30:24: "have pity on your own soul, pleasing God." Hence Jesus began to do and to teach. "Be earnest in these things," that is, exercise them earnestly. 2 Timothy 4:2: "be earnest in season." And the fruit from this will be abundant, because "in doing this, both yourself," etc. And this is a great thing. James 5:20: "he who causes a sinner to be converted from the error of his way shall save his soul from death." Daniel 12:3: "those who instruct many unto justice, as stars," etc. Hence to teachers is owed the reward of the aureole. Then when he says "the elder," etc., he shows how he ought to impart his teaching differently to different people, and he sets forth two diversities: one according to age; the other according to sex. According to age: first as to men, second as to women, at "the elder women," etc. He says therefore, "the elder," etc., "but entreat him as a father," Leviticus 19:32: "honor the person of the aged." And therefore they are not to be rebuked bitingly, but to be entreated. 1 Peter 5:1: "the elders who are among you, I, a fellow elder, entreat." And if Peter, an elder, did this, how much more ought a young man to do this? But against this, Isaiah 65:20: "the child of a hundred years shall die, and the sinner of a hundred years shall be accursed." I answer: it must be said that an old man, on account of exceeding malice, loses the honor of old age, and then he is to be rebuked. "The young men, as brothers." Matthew 23:8: "you are all brothers." Ezekiel 34:4: "with austerity you will rule over them." On the part of women there is a difference of ages, because "the elder women as mothers," especially those who are not young; below, 5:3: "honor widows." "The younger, as sisters," out of the love of charity. And this, "in all chastity." Because spiritual love toward women, unless it is cautious, degenerates into carnal love, therefore in those things which pertain to young women, chastity must be applied; and therefore the Apostle adds this. Hence the Pope, writing to them, says: "to the beloved in Christ." But to men he says simply: "to the beloved sons."”

Post-Reformation

c. 1650 – 1900
1771
A.D.
John Gill Reformed
1697–1771
“Take heed unto thyself,.... Not as a man, or a Christian only, but as a minister; and as every minister should take heed to his life and conversation, that it be exemplary, as in Ti1 4:12 to his gifts, that they be not lost, or neglected, but used and improved; to the errors and heresies abroad, that he be not infected with them; and to his flock, which is the other part of himself, that he feed it with knowledge and understanding: and to thy doctrine: preached by him, that it be according to the Scriptures, be the doctrine of Christ, and his apostles, and according to godliness; that it tend to edification, and is pure, incorrupt, and all of a piece; and that it be expressed in the best manner, with all boldness and plainness; and that he defend it against all opposition: continue in them; or "with them"; the members of the church at Ephesus; or rather in the doctrines of the Gospel; which should be done, though a majority is against them; though rejected by the wise, learned, and rich; though not to be comprehended by carnal reason; and though loaded with reproach and scandal; and though persecuted, yea even unto death for them: for in doing this, thou shall both save thyself; a minister by taking heed to himself, and doctrine, saves himself from the pollutions of the world, from the errors and heresies of false teachers, from the blood of all men, and from all just blame in his ministry. And them that hear thee; by being an example to them in doctrine and conversation, a minister is the means of saving and preserving those that attend on him, from erroneous principles, and immoral practices; and by faithfully preaching the Gospel to his hearers, he is instrumental in their eternal salvation; for though Jesus Christ is the only Saviour, the only efficient and procuring cause of salvation, yet the ministers of the Gospel are instruments by which souls believe in him, and so are saved; the word preached by them, being attended with the Spirit of God, becomes the ingrafted word, which is able to save, and is the power of God unto salvation; and nothing can more animate and engage the ministers of the word to take heed to themselves and doctrine, and abide therein, than this, of being the happy instruments of converting sinners, and saving them from death; see Next: 1 Timothy Chapter 5”
Source
1832
A.D.
Adam Clarke Methodist
1762–1832
“Meditate upon these things - Ταυτα μελετα· Revolve them frequently in thy mind; consider deeply their nature and importance; get them deeply fastened in thy heart, and let all thy conduct flow from this inward feeling and conviction. Let the nature, reasons, and motives of thy ministry, be ever in the view of thy heart and conscience. Give thyself wholly to them - Εν τουτοις ισθι· Be thou in these things. Horace has a similar expression: Omnis in hoc sum. "I am absorbed in this." Occupy thyself wholly with them; make them not only thy chief but thy sole concern. Thou art called to save thy own soul, and the souls of them that hear thee; and God has given thee the Divine gifts for this and no other purpose. To this let all thy reading and study be directed; this is thy great business, and thou must perform it as the servant and steward of the Lord. Bengel has a good saying on this verse, which I will quote: In his qui est, minus erit in sodalitatibus mundanis, in studiis alienis, in colligendis libris, conchis, nummis, quibus multi pastores notabilem aetatis partem insistentes conterunt; "He who is wholly in these things will be little in worldly company, in foreign studies, in collecting books, shells, and coins, in which many ministers consume a principal part of their life." Such persons are worthy of the deepest reprehension, unless all these studies, collections, etc., be formed with the express view, of illustrating the sacred records; and to such awful drudgery few Christian ministers are called. Many, when they have made such collections, seem to know nothing of their use; they only see them and show them, but can never bring them to their assistance in the work of the ministry. These should be prayed for and pitied. That thy profiting may appear to all - By being made a universal blessing; convincing and converting sinners; and building up the Church of God on its most holy faith.”
Source
1871
A.D.
1871
“Meditate--Greek, "Meditate CAREFULLY upon" (Psa 1:2; Psa 119:15; compare "Isaac," Gen 24:63). these things-- (Ti1 4:12-14). As food would not nourish without digestion, which assimilates the food to the substance of the body, so spiritual food, in order to benefit us, needs to be appropriated by prayerful meditation. give thyself wholly to--literally, "BE in these things"; let them engross thee wholly; be wholly absorbed in them. Entire self-dedication, as in other pursuits, so especially in religion, is the secret of proficiency. There are changes as to all other studies, fashionable to-day, out of fashion to-morrow; this study alone is never obsolete, and when made the all-engrossing aim sanctifies all other studies. The exercise of the ministry threatens the spirit of the ministry, unless it be sustained within. The minister must be first his own scholar before he can be another's teacher. profiting--Greek, "progress" towards perfection in the Christian life, and especially towards the fullest realization of the ideal of a Christian minister (Ti1 4:12). may appear to all--not for thy glory, but for the winning of souls (Mat 5:16).”
Source
Modern · 1953 →

The in-app commentary runs from the Fathers to the early-modern record, then stops — that's where the public-domain sources end, not where the reading does. For the modern reading, follow the sources directly.