The interpretation timeline
Matthew 5:26 Douay-Rheims

Amen I say to thee, thou shalt not go out from thence till thou repay the last farthing.

A.D. 420 – 1871 5 witnesses 6 excerpts

Patristic

before A.D. 750
420
A.D.
Jerome Patristic
c. A.D. 347–420
“A farthing is a coin containing two mites. What He says then is, ‘Thou shalt not go forth thence till thou hast paid for the smallest sins.’”
430
A.D.
Augustine of Hippo Patristic
A.D. 354–430
“(ubi sup.) By the prison I understand the punishment of the darkness. And that none should despise that punishment, He adds, Verily I say unto thee, thou shalt not come out thence till thou hast paid the very last farthing.”
“(ubi sup.) Or it is an expression to denote that there is nothing that shall go unpunished; as we say ‘To the dregs,’ when we are speaking of any thing so emptied that nothing is left in it. Or by the last farthing (quadrans.) may be denoted earthly sins. For the fourth and last element of this world is earth. Paid, that is in eternal punishment; and until used in the same sense as in that, Sit thou on my right hand until I make thy enemies thy footstool; (Ps. 110:1.) for He does not cease to reign when His enemies are put under His feet. So here, until thou hast paid, is as much as to say, thou shalt never come out thence, for that he is always paying the very last farthing while he is enduring the everlasting punishment of earthly sins.”
Source

Scholastic

c. 1100 – 1500
1256
A.D.
Thomas Aquinas Catholic
1225–1274
“"If therefore you offer." Here he forbids inveterate anger, from which hatred is born, and he argues from the greater, according to Rabanus, thus: if it is not lawful for you to be angry with your brother, much more is it not lawful to retain anger, whence hatred is born. Therefore "if you offer," that is, if you propose to offer, "at the altar." This is explained in many ways, according as "altar" is sometimes taken for the material temple, as in Psalm 25:6: "I will wash my hands among the innocent, and I will encompass your altar, O Lord." Sometimes it is taken for Christ; Lamentations 2:7: "The Lord has cast off his altar," that is, Christ, namely in the Passion. Sometimes for the devotion of the heart, and this is the interior temple, according to Augustine. As to the first, "if you offer your gift," that is, your oblation, "at the altar" — the material altar, taken literally; or the gift of a good work, according to the Gloss, "at the altar," that is, Christ. Or, according to Augustine: "your gift," that is, prayers, Psalms, hymns, and the like, "at the altar," that is, in the heart, which is the temple where you are about to offer; and "there," namely in the Church, or in the heart, "you remember that your brother has something against you." This can be understood in two ways, namely concerning the one who injures and the one who is injured. Concerning the one who injures, thus, according to Augustine: "if you remember," that is, if it comes into your mind and to your knowledge, that "your brother," whom you have injured, "has something against you" — namely on account of the disposition of an insult, of bodily injury, of the taking away of temporal goods, of the blackening of reputation — "leave there," namely before the altar, or before God, "your gift, and go": if he is absent, not with the feet of the body, as Augustine says, but you should prostrate yourself in humble mind in the sight of him to whom you are about to offer; if he is present, he must be called back to love, by seeking pardon from him. Or, if "your brother," who injured you, "has something against you," that is, whereby he is set against you, "go to be reconciled to your brother," by giving up your rancor toward him. For from the very fact that, in saying "if your brother has something against you," he does not add "justly," he gives us to understand that even the one to whom the injury was done ought to seek friendship. Hence Chrysostom says: if for the glory of your salvation the Lord commands you to make friendship, much more ought you to ask for it, so that you may attain a double glory: one, because you are innocent; the other, because you asked first. "And then, coming" — as one now pleasing to the Lord, whereas before you did not please him — "you shall offer your gift." Chrysostom: if you have offended in thought, be reconciled in thought; if in words, in words; if in deeds, in deeds. And again: unless you appease by deeds the one whom you have injured by deeds, you pray to the Lord in vain, you give alms in vain from the things by which you have despoiled others. For what does it profit if one man prays to the Lord for you, and another cries out to the Lord against you? Ecclesiasticus 34:23: "The Most High does not approve the gifts of the wicked." And note here four things which are required for the giving or offering: first, cheerfulness of mind; hence he says "if you offer"; Ecclesiasticus 35:11: "In every gift make your countenance cheerful." Second, ownership of the thing; hence he says "your gift"; Proverbs 3:9: "Honor God with your substance." Third, the fitness of the place, "at the altar." Fourth, love of neighbor; hence he says "and you remember"; 1 Corinthians 13:3: "If I distribute all my goods to feed the poor, but have not charity, it profits me nothing." He is foolish who loses an abundance of food for the sake of a penny's worth of salt, that is, of charity, which gives savor and beauty to all things, as gold does to other metals. "Be at agreement with your adversary." Above he forbade having anger, or discord, with one's brothers; here he removes having discord with an adversary, saying "be agreeing," that is, benevolent or kindly — as is gathered from the Greek, as Jerome says — "with your adversary." An objection: the Devil is an adversary; therefore one must agree with him. Response: he speaks of the one who is with us on the way; but the Devil is not on the way, nor can he be, but is in eternal straying from the way; hence "your adversary," according to Chrysostom, means a man who opposes, or literally an enemy; Romans 12:18: "If it be possible, as much as is in you, having peace with all men." "While," that is, until, "you are with him in the way," that is, in the state of meriting; John 9:4: "The time is coming when no one can work." Or our adversary is God, of whom Exodus 23:7 says: "I am the Lord, who am an adversary to the wicked." Or it is the divine word, which is opposed to those willing to sin; 2 Timothy, penultimate chapter, 16: "All Scripture, divinely inspired, is useful for teaching, for reproving." Or it is the remorseful conscience, of which Psalm 49:21 says: "I will reprove you, and set myself against your face." And thus, again, it is explained according to all these ways. Hence, "be agreeing with your adversary," that is, with God, and with the divine word, according to Augustine and Bede, with whom one must agree in the hope of the promise, in the fear of punishment, in the carrying out of the precept, in the avoidance of what is forbidden. "Quickly," that is, without delay; Ecclesiasticus 5:8: "Do not delay to be converted to the Lord." "While you are with him," that is, with him with whom you shall walk rightly "in the way," namely the way of Christ, or of penance, or of the world; Psalm 118:32: "I have run the way of your commandments, when you enlarged my heart." "Lest perhaps he deliver you." According to Augustine, "lest perhaps" means lest it become, as it were by occasion, the cause of your being delivered up. And he says "perhaps," according to the Gloss, lest the place of repentance be taken away. For if the adversary had died before he agreed — or had been well-disposed — it would seem that he would be condemned, were it said simply and without qualification, "lest the adversary" — that is, the divine word, or God, or the remorseful conscience — "deliver you to the judge." The Gloss: into the hands of Christ. John 5:22: "he has given all judgment to the Son." And "the judge" is Christ; Jeremiah 29:23: "I am the judge, and the witness." "Deliver you to the officer": the Gloss says, that is, to the Angel who gathers the tares in order to seize them, below, chapter 13; Psalm 103:4: "who makes his Angels spirits." Or "to the officer," that is, to the Devil, the exactor; Isaiah 14:4: "How has the exactor ceased?" "And you be cast into prison," that is, into the abyss of Hell; Isaiah 24:22: "they shall be shut up in prison"; Revelation 20:3: "he cast him into the abyss, and shut him up." "Amen I say to you," that is, know for certain, that you shall not go out from there, "until" — the Gloss: that is, never. Hence Augustine: "until" does not here signify the end of the punishment, but the continuation of the misery. As if he were to say: you shall always be paying, and never fully pay off; as in Psalm 109:1: "Sit at my right hand, until I make your enemies your footstool," that is, you shall sit forever. "You pay the last farthing," that is, the smallest sins, according to Bede and Rabanus, because nothing will remain unpunished — for the farthing is a kind of coin having two mites. Or, according to Augustine and Jerome, by "farthing" he meant to signify earthly sins: for the last farthing is earth, which is the fourth part of the elements of this world, and the last from fire; as if he were to say: because you were unwilling to be fire through charity, air through the vigor of good work, water through the sanctification of Baptism, but were earthly by clinging to earthly things, you shall not go out from there, because you shall never fully pay off the sins which you contracted from the earth.”

Post-Reformation

c. 1650 – 1900
1771
A.D.
John Gill Reformed
1697–1771
“Verily, I say unto thee,.... This may be depended upon, you may assure yourself of it, that thou shalt by no means come out thence, from prison, till thou hast paid the uttermost farthing, or "last farthing"; or as the Ethiopic version reads it, "till thou hast exactly paid all"; which seems to express the inexorableness of the creditor, and the impossibility of the debtor's release.”
Source
1871
A.D.
1871
“Verily I say unto thee, Thou shalt by no means come out thence, fill thou hast paid the uttermost farthing--a fractional Roman coin, to which our "farthing" answers sufficiently well. That our Lord meant here merely to give a piece of prudential advice to his hearers, to keep out of the hands of the law and its officials by settling all disputes with one another privately, is not for a moment to be supposed, though there are critics of a school low enough to suggest this. The concluding words--"Verily I say unto thee, Thou shalt by no means come out," &c.--manifestly show that though the language is drawn from human disputes and legal procedure, He is dealing with a higher than any human quarrel, a higher than any human tribunal, a higher than any human and temporal sentence. In this view of the words--in which nearly all critics worthy of the name agree--the spirit of them may be thus expressed: "In expounding the sixth commandment, I have spoken of offenses between man and man; reminding you that the offender has another party to deal with besides him whom he has wronged on earth, and assuring you that all worship offered to the Searcher of hearts by one who knows that a brother has just cause of complaint against him, and yet takes no steps to remove it, is vain: But I cannot pass from this subject without reminding you of One whose cause of complaint against you is far more deadly than any that man can have against man: and since with that Adversary you are already on the way to judgment, it will be your wisdom to make up the quarrel without delay, lest sentence of condemnation be pronounced upon you, and then will execution straightway follow, from the effects of which you shall never escape as long as any remnant of the offense remains unexpiated." It will be observed that as the principle on which we are to "agree" with this "Adversary" is not here specified, and the precise nature of the retribution that is to light upon the despisers of this warning is not to be gathered from the mere use of the word "prison"; so, the remedilessness of the punishment is not in so many words expressed, and still less is its actual cessation taught. The language on all these points is designedly general; but it may safely be said that the unending duration of future punishment--elsewhere so clearly and awfully expressed by our Lord Himself, as in Mat 5:29-30, and Mar 9:43, Mar 9:48 --is the only doctrine with which His language here quite naturally and fully accords. (Compare Mat 18:30, Mat 18:34). The Same Subject Illustrated from the Seventh Commandment (Mat 5:27-32).”
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.