The interpretation timeline
Exodus 34:6 Douay-Rheims

And when he passed before him, he said: O the Lord, the Lord God, merciful and gracious, patient and of much compassion, and true,

1105 – 1871 6 witnesses

Scholastic

c. 1100 – 1500
1105
A.D.
Rashi Jewish
1040–1105
ה׳ ה׳ THE LORD, THE LORD — This is the attribute of Divine mercy. The one (the first ה׳) alludes to God having mercy on the sinner before he sins and the other after he has sinned and repented (Rosh Hashanah 17b). אל GOD — This is also an attribute of Divine mercy (it is not, as אלהים, an attribute of stern justice). Thus also does Scripture say, (Psalms 22:2) “My God, my God (אלי ,אלי) why hast Thou forsaken me?” — for surely one would not say to the attribute of stern Justice “why hast Thou forsaken me?”! Thus have I found in the Mechilta d'Rabbi Yishmael 15:2:2. ארך אפים SLOW TO ANGER — He defers (מאריך) His anger and does not hasten to punish — it may be that the sinner will repent. ורב חסד AND ABUNDANT IN MERCY — to those who need mercy because they have not sufficient merits to be saved by them. ואמת AND TRUTH — faithfully rewarding those who perform His will.”
Source
1270
A.D.
Ramban Jewish
1194–1270
“AND THE ETERNAL PASSED BY BEFORE HIM. This means that He fulfilled His promise to Moses, I will make all My goodness pass before thee. AND HE PROCLAIMED: ‘HASHEM HASHEM E-IL’ (THE ETERNAL, THE ETERNAL, G-D). These three words are sacred Names of G-d which the Sages call midoth (attributes), being that they constitute the attribute of the Lord of repentance, the attribute of His mercies and that of His goodness. as separate attributes. See, however, Guide of the Perplexed, Vol. I, p. 193, Note 5, in Friedlander’s translation. The Proper Name of G-d [i.e. the Tetragrammaton], however does not lend itself to any plural form.] does not lend itself to any plural form, in spite of the fact that the various attributes are here cited (Abusaula). And the attributes which are perceived in human terms are ten: merciful and gracious, etc. Thus on one side they are all attributes, and on the other, there are the three which denote the Names of His essence, whereas the Ten are attributes. Now the attributes also represent Names of G-d, for merciful and gracious, long-suffering etc. are all with reference to the essence of G-d the Most High. Therefore it does not say “the G-d Who has mercy, grace, and is long-suffering,” for [that would have meant that these are His ways with the lower creatures; instead it says, merciful and gracious, long-suffering, indicating] that these actions emanate from G-d’s attributes, [which are His essence]. And abounding in goodness and truth; keeping mercy upon the thousandth generation — these three denote the attribute of mercy, since He increases the goodness over His strength and might and the truth in His mercies. And ‘notzeir’ (keeping) mercy unto the thousandth generation, for He hath remembered His mercy and His faithfulness toward the house of Israel. Or it may be that the word notzeir means “sprouting,” of the root, ‘v’neitzer’ (and a twig) shall grow forth out of his roots. And in His goodness He is ‘nosei’ (forgiving) iniquity and transgression and sin. This is of the expression, I have made, and I ‘esa’ (will bear). The two phrases, and that will by no means clear the guilty, and visiting the iniquity of the fathers upon the children, are an explanation to the one of forgiving iniquity [mentioned before]. It is called an “attribute” because He clears the sinner by this visitation. And because this act of forgiving is not equal for iniquity, transgression and sin, but instead in each category has its own form of clearing the sinner, it is called in each case “one attribute.” etc., also constitute an independent attribute, for the ‘clearing’ done in this form of forgiving is by visitation, it being another way of forgiveness of sin, that He will not forgive it outright, but visit it upon the generations etc.” (Abusaula). Now Moses bowed his head to G-d Who passed by before him, and prayed that G-d should always go in their midst and forgive their iniquity and their sin in whatever they might do, and that He cause them to inherit the Land. Moses, however, did not ask that G-d forgive “our transgressions,” since it is not possible that G-d forgive transgressions, which are sins of a rebellious nature; in those cases He is only to bear them [through visitation] and not to destroy them. It will not be concealed from you why these two Names [If now I have found grace in Thy sight, O Lord, let the Lord, I pray Thee, go in the midst of us…] are written with Aleph Daleth [instead of in the letters of the Tetragrammaton];. Thus the first Name is in place of the Tegragrammaton, and Moses prayed that the Lord [written in Aleph Daleth] go in our midst in the absolute perfection of the Unity of the two Names (Abusaula). it is for this reason that G-d said, Behold, I make a covenant, until [all people shall see…] the work of the Eternal that it is tremendous.”
Source

Post-Reformation

c. 1650 – 1900
1771
A.D.
John Gill Reformed
1697–1771
“And the Lord passed by before him,.... Or caused his Shechinah, his divine Majesty, and the glory of it, to pass before him, as the Targums; his glory and goodness, which he had promised should pass before him, Exo 33:19 and it is but a transient passing view the greatest of men, God's peculiar favourites, have of him in this life: and proclaimed, the Lord, the Lord God; the Jerusalem Targum wrongly paraphrases the words as a prayer of Moses thus, "and Moses prayed, and said, O Lord, Lord"; and so the Vulgate Latin version; but it is quite clear, and beyond all doubt, from Num 14:17 that what follow are the words of God, and not of Moses: the sense is, that the Lord, as he passed by Moses, to raise and fix his attention, declared it was Jehovah that passed by; which is repeated the more to excite his attention, and is the name by which he had made himself known to Moses, even when he sent him into Egypt; for "I am that I am" is an explanation of this name, see Exo 3:14 and the word "El", translated "God", signifies mighty and powerful, and is true of all the three divine Persons, to whom respect may be had in the use of these three words. What is proclaimed or declared concerning God is, that he is merciful and gracious, longsuffering, and abundant in goodness and truth; first "merciful", and he is so in the most tender and affectionate manner; he is rich and plenteous in mercy, freely giving it, delights in bestowing it, constantly shows it to his people; it is manifested and displayed in Christ, the mercy seat; and it lays a foundation for faith and hope, and is the spring of all good things in time, and to eternity: and he is also "gracious", good and kind to men, without any merit or desert of theirs, but bestows good things on them freely, of his own free grace, favour, and good will, as appears by various acts of his; in the eternal choice of them to everlasting happiness; in providing a Saviour for them, and giving all grace and spiritual blessings to them in him; by giving Christ to them, and for them, justifying them freely by his righteousness, pardoning their sins according to the riches of his grace, regenerating, calling, preserving, and saving them by it: likewise "longsuffering"; both towards wicked men, the vessels of wrath, by whom his patience and longsuffering are abused and despised; and towards his elect, on whom he waits to be gracious, not willing that any of them should perish, but all be brought to repentance; and his longsuffering is their salvation: and it follows, "abundant in goodness and truth"; in providential goodness to all men; in special goodness to his chosen people, which he has laid up, and wrought out for them, and shown them in Christ; in his truth and faithfulness, in fulfilling his promises, both with respect to the mission of his Son into the world, to be the Saviour of it, and with respect to all other things promised, whether relating to this life, or that to come, to grace or glory; he never suffers his truth and faithfulness to fail; his promises are all yea and amen in Christ.”
Source
1832
A.D.
Adam Clarke Methodist
1762–1832
“And the Lord passed by - and proclaimed, The Lord, etc. - It would be much better to read this verse thus: "And the Lord passed by before him, and proclaimed Jehovah," that is, showed Moses fully what was implied in this august name. Moses had requested God to show him his glory, (see the preceding chapter, Exo 33:18 (note)), and God promised to proclaim or fully declare the name Jehovah, (Exo 33:19); by which proclamation or interpretation Moses should see how God would "be gracious to whom he would be gracious," and how he would "be merciful to those to whom he would show mercy. Here therefore God fulfils that promise by proclaiming this name. It has long been a question, what is the meaning of the word יהוה Jehovah, Yehovah, Yehue, Yehveh, or Yeve, Jeue, Jao, Iao, Jhueh, and Jove; for it has been as variously pronounced as it has been differently interpreted. Some have maintained that it is utterly inexplicable; these of course have offered no mode of interpretation. Others say that it implies the essence of the Divine nature. Others, that it expresses the doctrine of the Trinity connected with the incarnation; the letter י yod standing for the Father, ה he for the Son, and ו vau (the connecting particle) for the Holy Spirit: and they add that the ה he being repeated in the word, signifies the human nature united to the Divine in the incarnation. These speculations are calculated to give very little satisfaction. How strange is it that none of these learned men have discovered that God himself interprets this name in Exo 34:6,! "And the Lord passed by before him, and proclaimed יהוה Yehovah the Lord God, merciful and gracious, long-suffering, and abundant in goodness and truth, keeping mercy for thousands, forgiving iniquity and transgression and sin, and that will by no means clear the guilty." These words contain the proper interpretation of the venerable and glorious name Jehovah. But it will be necessary to consider them in detail. The different names in this and the following verse have been considered as so many attributes of the Divine nature. Commentators divide them into eleven, thus: - 1. יהוה Jehovah. 2. אל EL, the strong or mighty God. 3. רחום Rachum, the merciful Being, who is full of tenderness and compassion. 4. חנון Channun, the gracious One; he whose nature is goodness itself; the loving God. 5. ארך אפים Erech Appayim, long-suffering; the Being who, because of his goodness and tenderness, is not easily irritated, but suffers long and is kind. 6. רב Rab, the great or mighty One. 7. חסד Chesed, the bountiful Being; he who is exuberant in his beneficence. 8. אמת Emeth, the truth or true One; he alone who can neither deceive nor be deceived, who is the fountain of truth, and from whom all wisdom and knowledge must be derived. 9. נצר חסד Notser Chesed, the preserver of bountifulness; he whose beneficence never ends, keeping mercy for thousands of generations, showing compassion and mercy while the world endures. 10. נשא עון ופשע וחטאה Nose avon vaphesha vechattaah, he who bears away iniquity and transgression and sin: properly, the Redeemer, the Pardoner, the Forgiver; the Being whose prerogative alone it is to forgive sin and save the soul. ינקה(לו) נקה לא Nakkeh lo yenakkeh, the righteous Judge, who distributes justice with an impartial hand, with whom no innocent person can ever be condemned. 11. פקד עון Poked avon, etc.; he who visits iniquity, who punishes transgressors, and from whose justice no sinner can escape. The God of retributive and vindictive justice. These eleven attributes, as they have been termed, are all included in the name Jehovah, and are, as we have before seen, the proper interpretation of it; but the meaning of several of these words has been variously understood.”
Source
1849
A.D.
1774–1849
“He said. Some refer this to Moses; others, more probably, to God, who had promised, by this signal of the name of the Lord, to testify his presence. (Calmet) — The angel addresses God in this manner, while Moses lies concealed in the rock, covered with the hand or cloud of God’s representative. (Haydock) — Of the eleven attributes here claimed by God, three regard his essence, six his mercy, and the last two his justice. (Calmet)”
Source
1871
A.D.
1871
“the Lord passed by before him--in this remarkable scene, God performed what He had promised to Moses the day before. proclaimed, The Lord . . . merciful and gracious--At an earlier period He had announced Himself to Moses, in the glory of His self-existent and eternal majesty, as "I am" [Exo 3:14]; now He makes Himself known in the glory of His grace and goodness--attributes that were to be illustriously displayed in the future history and experience of the church. Being about to republish His law--the sin of the Israelites being forgiven and the deed of pardon about to be signed and sealed by renewing the terms of the former covenant--it was the most fitting time to proclaim the extent of the divine mercy which was to be displayed, not in the case of Israel only, but of all who offend.”
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.