The interpretation timeline
Isaiah 1:17 Douay-Rheims

Learn to do well: seek judgment, relieve the oppressed, judge for the fatherless, defend the widow.

A.D. 99 – 1875 9 witnesses 11 excerpts

Patristic

before A.D. 750
99
A.D.
Clement of Rome Patristic
d. A.D. 99
“The ministers of the grace of God have, by the Holy Spirit, spoken of repentance; and the Lord of all things has himself declared with an oath regarding it, "As I live, says the Lord, I desire not the death of the sinner, but rather his repentance;" [Ezekiel 33:11] adding, moreover, this gracious declaration, "Repent, O house of Israel, of your iniquity." [Ezekiel 18:30] Say to the children of my people, Though your sins reach from earth to heaven, and though they be redder than scarlet, and blacker than sack-cloth, yet if you turn to me with your whole heart, and say, Father! I will listen to you, as to a holy people. [2 Chronicles 7:14] And in another place He speaks thus: "Wash you and become clean; put away the wickedness of your souls from before my eyes; cease from your evil ways, and learn to do well; seek out judgment, deliver the oppressed, judge the fatherless, and see that justice is done to the widow; and come, and let us reason together. He declares, Though your sins be like crimson, I will make them white as snow; though they be like scarlet, I will whiten them like wool. And if you be willing and obey me, you shall eat the good of the land; but if you refuse, and will not hearken unto me, the sword shall devour you, for the mouth of the Lord has spoken these things." [Isaiah 1:16-20] Desiring, therefore, that all His beloved should be partakers of repentance, He has, by His almighty will, established [these declarations].”
Source
220
A.D.
Tertullian Patristic
c. A.D. 150–220
“God offers a brief summary through the prophet Isaiah of the honor that widows enjoy in the sight of God.… The Father defends these two types of people [widows and orphans] through divine mercy in proportion to their being destitute of human aid. Look how the widow's benefactor is put on a level with the widow herself, whose champion shall "reason with the Lord."”
Source
407
A.D.
John Chrysostom Patristic
A.D. 347–407
“Do you see the great importance God places on mercy and of standing up for those who have been treated unjustly? We should pursue these good works, and by the grace of God will we receive the blessings to come.”
“If you must visit someone, prefer to pay honor to orphans, widows and those in want rather than those who enjoy reputation and fame.”
“If you have pity on the widow, your sins are washed away.”

Scholastic

c. 1100 – 1500
1105
A.D.
Rashi Jewish
1040–1105
“Learn It is punctuated ‘raphe,’ weak, without a dagesh. This is from the form לָמֹד, learn to do good. One who teaches himself is of the ‘kal’ form. Therefore, its imperative plural is voweled with a ‘chirik’ like אִמְרוּ, שִׁמְעוּ, but one who teaches others is of the form of the ‘heavy conjugation’ (pi’el) with a ‘dagesh,’ and if one comes to command a number of people, the word is voweled לַמְּדוּ. And so, דִּרְשׁוּ, from the form דְרשׁ, but אַשְּׁרוּ in which the ‘shin’ has a ‘dagesh,’ is from the ‘heavy conjugation,’ and from the form אַשֵּׁר ; therefore, the imperative plural is voweled with a ‘patach’ like בַּשְּׂרוּ, סַפְּרוּ, דַּבְּרוּ. strengthen the robbed Heb. אַשְּׁרוּ חָמוֹץ. This is a Mishnaic term, אֲשַׁרְנוּהִי, “we have verified it” (Ketuboth 21a); “if I had strength (אֲיַשֵּׁר)” (Gittin 30b); “May your strength be strengthened (יִישַׁר)” (Shabbath 87a). Another explanation is: Lead him in the path of truth to acquire what rightfully belongs to him. An expression of: (Job 23:11) “My foot held its path (בֲּאֲשׁוּרוֹ)”; (Prov. 23:19) “And go (וְאַשֵׁר) in the way of your heart.” (perform justice So-and-so is innocent and so-and- so is guilty. plead the case of the widow Endeavor in their quarrel to plead for her, for she cannot go out to pursue her opponents.) the robbed Heb. חָמוֹץ, similar to (Ps. 71:4) “from the hand of the unrighteous and the robber (וּמְחַמֵּץ).””
Source
1167
A.D.
Ibn Ezra Jewish
1089–1167
“להיטב=היטב To do well. It is infinitive. אשרו Straighten. Root א ; ישר replaces the radical י ; the reverse is the case in תתאמרו=תִּתְיַמָּרוּ you shall boast yourselves(61:6). חמוץ Cruel. An adjective, like קרוב ‘ near ;’ comp. חומץ ‘ cruel ’ (Ps. 71:4). Many explain אשרו חמוץ Give due consideration to the cause, do not judge off hand ; the meaning of אשרו would then be, Praise ye (comp. Gen. 30:13).”
Source
1256
A.D.
Thomas Aquinas Catholic
1225–1274
“The new moon and the sabbath. Here he removes the celebrations of solemnities. And first, as to the future, he sets down the intent of the prohibition, saying, The new moon. Psalm 80: Blow the trumpet in the new moon, as a sign of your solemn day. The sabbath. Exodus 20: other festivities. Leviticus 23: these are the feasts of the Lord, which you shall call most solemn and most holy. Your assemblies are wicked. Below, 58: behold, in the day of your fast your own will is found, and you exact all your debtors. Second, at your Kalends, as to the present he sets down hatred, saying: Kalends, which above is the new moon. Whence in another Psalter: Sound the trumpet at the beginning of the month. Lamentations 2: the Lord hath delivered over to oblivion in Sion the festival and the sabbath, and to reproach and to the indignation of his fury the king and the priest. Third, as to the past, he sets down weariness, saying: they are become troublesome to me: and he sets down two things: the heaviness of the burden: they are become troublesome, Psalm 37: as a heavy burden they are become heavy upon me: second, the labor of the one who bears it: I have labored in enduring. Isaiah 43: thou hast made me to labor in thy iniquities. And he speaks of God after the manner of men: because it is said to be burdensome for a man to labor at what does not please him. And when you shall stretch forth. He reproves their prayers: and first he sets down the reproof; second the reason for the reproof, at, for your hands. Concerning the first he does two things. First he reproves as to the sign of devotion, at, and when you shall stretch forth. Lamentations 3: let us lift up our hearts with our hands to heaven, to God. And below, 65: all the day I have spread forth my hands to an unbelieving people, who walk in a way that is not good. Second, the prolixity of prayer (at: and when you shall multiply), Proverbs 28: he who turns away his ear that he may not hear the law, his prayer shall be execrable. For your hands are full of blood, which you have shed. Psalm 13: their feet are swift to shed blood. Proverbs 1: keep back thy foot from their paths: for their feet run to evil, and they make haste to shed blood. Wash yourselves. Here he sets down wholesome counsel; and concerning this he does three things. First he sets down the efficacious remedy; second the effect of the remedy, at, come; third the punishment against contempt, at, but if you will not. The remedy consists in two things: in the flight from evil and the following of good, at, learn. Evil is put to flight in two ways. By the purging of the past; and as to this he says, wash yourselves, Jeremiah 4: wash thy heart from malice, Jerusalem, that thou mayest be saved: how long shall hurtful thoughts abide in thee? Second, by caution as to the future: and this comes about in three ways. That he not think evil in his heart: be clean. Proverbs 22: he who loves cleanness of heart, for the grace of his lips shall have the king for his friend. That he not fulfill in deed what he has thought: Micah 2: woe to them that devise that which is unprofitable, and work evil in their beds: in the morning light they do it. Take away the evil, namely, the deed. That he not complete what he has begun: cease to act perversely. Jeremiah 2: keep back thy foot from being bare, and thy throat from thirst. A swift runner explaining his ways, in the same, 2. Learn to do well. Here he sets down the remedy as to the following of good: and first that they may learn it; second that they may fulfill it in deed, at, relieve the oppressed. For one works good in ordering himself; and as to this he says, learn to do well. Jeremiah 6: be instructed, Jerusalem, lest perhaps my soul depart from thee, lest perhaps I make thee a desert land, and uninhabitable. In relation to one's neighbor; and this is what he says, seek judgment. Job 29: the cause which I knew not, I searched out most diligently. Jeremiah 6: stand upon the ways, and see, and ask concerning the ancient paths. Relieve the oppressed. Here he sets down the fulfilling of the work in relieving the wretched. Now what makes one wretched is either violence: and as to this he says, relieve the oppressed: Proverbs 24: deliver them that are led to death, and cease not to free them that are drawn to destruction: or the ignorance of youth: judge for the fatherless: Ecclesiasticus 4: be to the fatherless as a father in judging: or the weakness of sex: defend the widow. Job 29: the ear that heard blessed me, and the eye that saw gave witness to me. And come. Here he promises the effect: and concerning this three things are set down. First, the obligation of the one who promises, when he says, come; as if he were to say: if you do what I say, and what I promise does not follow, I bind myself to this, that you may accuse me. This Job lamented, 9: there is none that can reprove both, and lay his hand between the two. Second, the cessation of evils: if your sins be. And he promises specifically the cleansing from sins: because when the cause ceases, the effect ceases; he touches on two kinds of sin. That which is from burning love, which is noted in the scarlet on account of its intense redness, against which he sets the whiteness of cold snow. Job 9: if I shall be washed as it were with snow waters, and my hands shall shine ever so clean, et cetera. And that which is sin from deadening fear, which is noted in the crimson, whose color approaches whiteness: against which he sets wool: Ezekiel 27: in the multitude of divers riches, in wools of the best color; Matthew 28: his countenance, etc.; Daniel 7: his garment white as snow, and his hair like white wool. Third, the restitution of good things is set down: if you be willing, and will hearken, the good things of the land. Psalm 26: I believe to see the good things of the Lord in the land of the living. You shall eat. Below, 65: behold my servants shall eat, and you shall be hungry. But if you will not. He sets down the punishment against contempt. And first he sets down the contempt, saying: but if you will not, Zechariah 8: I thought to afflict you, when your fathers provoked me to wrath. Second, he threatens the sword of vengeance; the sword shall devour you. Ezekiel 5: I will draw the sword after them, and I will accomplish my fury, and I will cause my indignation to rest upon them. Third, he shows the judgment to be unchangeable: for the mouth of the Lord hath spoken. Numbers 23: God is not as a man, that he should lie, nor as the son of man, that he should be changed.”

Post-Reformation

c. 1650 – 1900
1771
A.D.
John Gill Reformed
1697–1771
“Learn to do well,.... Which men are naturally ignorant of; to do good they have no knowledge; nor can they that are accustomed to do evil learn to do well of themselves; but the Lord can teach them to profit, and of him they should ask wisdom, and desire, under the influence of his grace, to learn to maintain good works for necessary uses, and particularly to do acts of beneficence to all men, and especially to the household of faith; and also, the following ones, seek judgment; seek to do justice between man and man in any cause depending, without respect of persons: relieve the oppressed; the poor that are oppressed by their neighbours that are richer and mightier than they, right their wrongs, and deliver them out of the hands of their oppressors (i): judge the fatherless; do justice to them who have none to take care of them, and defend them: plead for the widow; that is desolate, and has none to plead her cause. (i) Misn. Sabbat, c. 9. sect. 3. T. Bab. Yoma, fol. 67. 1,”
Source
1871
A.D.
1871
“seek judgment--justice, as magistrates, instead of seeking bribes (Jer 22:3, Jer 22:16). judge--vindicate (Psa 68:5; Jam 1:27).”
1875
A.D.
Keil & Delitzsch Lutheran
1861–1875
“Five admonitions relating to the practice of what is good: "Learn to do good, attend to judgment, set the oppressor right, do justice to the orphan, conduct the cause of the widow." The first admonition lays the foundation for the rest. They were to learn to do good - a difficult art, in which a man does not become proficient merely by good intentions. "Learn to do good:" hetib is the object to limdu (learn), regarded as an accusative; the inf. abs. הרע in Isa 1:16 takes the place of the object in just the same manner. The division of this primary admonition into four minor ones relating to the administration of justice, may be explained from the circumstance that no other prophet directs so keen an eye upon the state and its judicial proceedings as Isaiah has done. He differs in this respect from his younger contemporary Micah, whose prophecies are generally more ethical in their nature, whilst those of Isaiah have a political character throughout. Hence the admonitions: "Give diligent attention to judgment" (dârash, to devote one's self to a thing with zeal and assiduity); and "bring the oppressor to the right way." This is the true rendering, as Châmotz (from Châmatz, to be sharp in flavour, glaring in appearance, violent and impetuous in character) cannot well mean "the oppressed," or the man who is deprived of his rights, as most of the early translators have rendered it, since this form of the noun, especially with an immutable kametz like בּגוד בּגודה (cf., נקד נקּדּה), is not used in a passive, but in an active or attributive sense (Ewald, 152, b: vid., at Psa 137:8): it has therefore the same meaning as Chomeotz in Psa 71:4, and âshok in Jer 22:3, which is similar in its form. But if Châmotz signifies the oppressive, reckless, churlish man, אשּׁר cannot mean to make happy, or to congratulate, or to set up, or, as in the talmudic rendering, to strengthen (Luzzatto: rianimate chi oppresso); but, as it is also to be rendered in Isa 3:12; Isa 9:15, to lead to the straight road, or to cause a person to keep the straight course. In the case before us, where the oppressor is spoken of, it means to direct him to the way of justice, to keep him in bounds by severe punishment and discipline. (Note: The Talmud varies in its explanation of Chamoz: in one instance it is applied to a judge who lets his sentence be thoroughly leavened before pronouncing it; in another the Chamuz is said to signify a person robbed and injured, in opposition to Chomez (b. Sanhedrin 35a). It is an instructive fact in relation to the idea suggested by the word, that, according to Joma 39b, a man who had not only taken possession of his own inheritance, but had seized upon another person's also, bore the nickname of ben chimzon as long as he lived.) In the same way we find in other passages, such as Isa 11:4 and Psa 72:4, severe conduct towards oppressors mentioned in connection with just treatment of the poor. There follow two admonitions relating to widows and orphans. Widows and orphans, as well as foreigners, were the protgs of God and His law, standing under His especial guardianship and care (see, for example, Exo 22:22 (21), cf., Exo 21:21 (20). "Do justice to the orphan" (Shâphat, as in Deu 25:1, is a contracted expression for shâphat mishpat): for if there is not even a settlement or verdict in their cause, this is the most crying injustice of all, as neither the form nor the appearance of justice is preserved. "Conduct the cause of the widows:" ריב with an accusative, as in Isa 51:22, the only other passage in which it occurs, is a contracted form for ריב ריב. Thus all the grounds of self-defence, which existed in the hearts of the accused, are both negatively and positively overthrown. They are thundered down and put to shame. The law (thorah), announced in Isa 1:10, has been preached to them. The prophet has cast away the husks of their dead works, and brought out the moral kernel of the law in its universal application.”
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.