The interpretation timeline
Psalm 102:8 Douay-Rheims

The ford is compassionate and merciful: longsuffering and plenteous in mercy.

A.D. 395 – 1771 3 witnesses

Patristic

before A.D. 750
395
A.D.
Gregory of Nyssa Patristic
c. A.D. 335–395
“God is not an expression, and he does not have his essence in voice or utterance. God is of himself what also he is believed to be. He is named by those who call on him, not what he is essentially (for the nature of him who alone is unspeakable), but he receives his names from what are believed to be his works in regard to our life. To take an instance ready at hand, when we speak of him as God, we so name him from his overlooking and surveying all things and seeing through the things that are hidden. But if his essence is prior to his works, and if we understand his works by our senses and express them in words as we are best able, why should we be afraid of calling things by words of later origin than themselves? For if we stop interpreting any of the attributes of God until we understand them, and if we understand them only by what his works teach us, and if his power precedes its exercise and depends on the will of God, while his will resides in the spontaneity of the divine nature, are we not clearly taught that the words that represent things are of later origin than the things themselves and that the words that are framed to express the operations of things are reflections of the things themselves? And that this is so, we are clearly taught by holy Scripture, by the mouth of great David, when, as by certain peculiar and appropriate names, derived from his contemplation of the works of God, he thus speaks of the divine nature: "The Lord is full of compassion and mercy, long-suffering, and of great goodness." Now what do these words tell us? Do they indicate his operations or his nature? No one will say that they indicate anything but his operations. At what time, then, after showing mercy and pity, did God acquire his name from the display of his works? Was it before a person's life began? But who was there to be the object of pity? Was it, then, after sin entered into the world? But sin entered after humankind. The exercise, therefore, of pity, and the name itself, came after humanity. What then? Will our adversary [Eunomius], wise as he is above the prophets, convict David of error in applying names to God derived from his opportunities of knowing him? Or, in contending with him, will he use against him the pretense in his stately passage as out of a tragedy, saying that "he glories in the most blessed life of God with names drawn from human imagination, whereas it gloried in itself alone, long before people were born to imagine them"? The psalmist's advocate will readily admit that the divine nature gloried in itself alone even before the existence of human imagination but will contend that the human mind can speak only so much in respect of God as its capacity, instructed by his works, will allow. "For," as says the Wisdom of Solomon, "by the greatness and beauty of the creatures proportionably the Maker of them is seen."”
Source
430
A.D.
Augustine of Hippo Patristic
A.D. 354–430
“"The Lord is full of compassion and mercy: long-suffering, and of great mercy" [Psalm 103:8]. Why so long-suffering? Why so great in mercy? Men sin and live; sins are added on, life continueth: men blaspheme daily, and "He maketh His sun to rise over the good and the wicked." [Matthew 5:45] On all sides He calleth to amendment, on all sides He calleth to repentance, He calleth by the blessings of creation, He calleth by giving time for life, He calleth through the reader, He calleth through the preacher, He calleth through the innermost thought by the rod of correction, He calleth by the mercy of consolation: "He is long-suffering, and of great mercy." But take heed lest by ill using the length of God's mercy, thou treasure up for thyself, as the Apostle saith, wrath in the day of wrath. ...For some there are who prepare to turn, and yet put it off, and in them crieth out the raven's voice, "Cras! Cras!" The raven which was sent from the ark, never returned. God seeketh not procrastination in the raven's voice, but confession in the wailing of the dove. The dove, when sent forth, returned. How long, To-morrow! To-morrow!? Look to thy last morrow: since thou knowest not what is thy last morrow, let it suffice that thou hast lived up to this day a sinner. Thou hast heard, often thou art wont to hear, thou hast heard to-day also; daily thou hearest, and daily thou amendest not. ...”
Source

Post-Reformation

c. 1650 – 1900
1771
A.D.
John Gill Reformed
1697–1771
“He will not always chide,.... He sometimes does chide his children, though never but when they have done a fault; always for their sins, in order to bring them to a sense and acknowledgment of them, and to depart from them; not for chiding sake, as some parents, to gratify their passion and ill humour, who correct for their own pleasure; but the Lord chides and corrects for the profit of his children, that they may be partakers of his holiness; he ever does it for their good, but he will not always chide, or continue it ever: or "he will not always contend" (e), strive with them, litigate a point with them, hold out a controversy, not being able to stand before him; he knows their frame, their weakness, and frailty; see Isa 57:16, neither will he keep his anger for ever; though he does with the wicked, yet not with his own people; that endures but for a moment, and is rather seeming than real; and what does appear is soon turned away; he does not retain it long, he is quickly pacified towards them for all they have done, and smiles again upon them, Mic 7:18. (e) "contendet", Pagninus, Montanus; "litigat", Junius & Tremellius, Piscator; "litigabit", Vatablus, Gejerus, Michaelis.”
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.