The interpretation timeline
Psalm 79:9 Douay-Rheims

Thou hast brought a vineyard out of Egypt: thou hast cast cut the Gentiles and planted it.

A.D. 430 – 1771 3 witnesses 4 excerpts

Patristic

before A.D. 750
430
A.D.
Augustine of Hippo Patristic
A.D. 354–430
“"A vineyard out of Egypt You have brought over, You have cast out the nations, and hast planted her" [Psalm 80:8]. It was done, we know. How many nations were cast out? Amorites, Cethites, Jebusites, Gergesites, and Evites: after whose expulsion and overthrow, there was led in the people delivered out of Egypt, into the land of promise. Whence the vineyard was cast out, and where she was planted, we have heard. Let us see what next was done, how she believed, how much she grew, what ground she covered.”
Source
“"A way You have made in the sight of her, and hast planted the roots of her, and she has filled the land" [Psalm 80:9]. Would she have filled the land, unless a way had been made in the sight of her? What was the way which was made in the sight of her? "I am," He says, "the Way, the Truth, and the Life." [John 14:6] With reason she has filled the land. That has now been said of this vineyard, which has been accomplished at the last. But in the mean time what? "She has covered the mountains with her shadow, and with her branch the cedars of God" [Psalm 80:10]. "You have stretched out her boughs even unto the sea, and even unto the river her shoots" [Psalm 80:11]. This requires the office of an expositor, that of a reader and praiser does not suffice: aid me with attention; for the mention of this vineyard in this Psalm is wont to overcloud with darkness the inattentive....But nevertheless the first Jewish nation was this vine. But the Jewish nation reigned as far as the sea and as far as the river. As far as the sea; it appears in Scripture [Numbers 34:5] that the sea was in the vicinity thereof. And as far as the river Jordan. For on the other side of Jordan some part of the Jews was established, but within Jordan was the whole nation. Therefore, "even unto the sea and even unto the river," is the kingdom of the Jews, the kingdom of Israel: but not "from sea even unto sea, and from the river even unto the ends of the round world;" this is the future perfection of the vineyard, concerning which in this place he has foretold. When, I say, he had foretold to you the perfection, he returns to the beginning, out of which the perfection was made. Of the beginning will you hear? "Even unto the river." Of the end will you hear? "He shall have dominion from sea even unto sea:" that is, "she has filled the earth." Let us look then to the testimony of Asaph, as to what was done to the first vineyard, and what must be expected for the second vineyard, nay to the same vineyard....What then, the vineyard before the sight whereof a way was made, that she should fill the earth, at first was where? "Her shadow covered the mountains." Who are the mountains? The Prophets. Why did her shadow cover them? Because darkly they spoke the things which were foretold as to come. You hear from the Prophets, Keep the Sabbath day, on the eighth day circumcise a child, offer sacrifice of ram, of calf, of he-goat. Be not troubled, her shadow does cover the mountains of God; there will come after the shadow a manifestation. "And her shrubs the cedars of God," that is, she has covered the cedars of God; very lofty, but of God. For the cedars are types of the proud, that must needs be overthrown. The "cedars of Lebanon," the heights of the world, this vineyard did cover in growing, and the mountains of God, all the holy Prophets and Patriarchs.”
Source

Scholastic

c. 1100 – 1500
1105
A.D.
Rashi Jewish
1040–1105
“You uprooted a vine from Egypt He went back and alluded to the exile of the Romans. The vine of Israel, which You uprooted from Egypt. You uprooted them from there, as (Job 19:10): “He has uprooted (ויסע) my hope like a tree.” Afterwards, You drove out the seven nations and planted Israel in their land.”

Post-Reformation

c. 1650 – 1900
1771
A.D.
John Gill Reformed
1697–1771
“The hills were covered with the shadow of it,.... Alluding to the land of Canaan, which was a mountainous and hilly country, at least some part of it; hence we read of the hill country of Judea, Luk 1:39 and to the nature of vines, which delight to grow on hills and mountains (p): in a figurative sense this may denote the subjection of kings and kingdoms, comparable to hills, to the Israelites in the times of David and Solomon, Sa2 8:1 and the exaltation of the church of Christ, in the latter day, over the hills and mountains, Isa 2:2. The Targum is, "the mountains of Jerusalem were covered with the shadow of the house of the sanctuary, and of the houses of the schools:'' and the boughs thereof were like the goodly cedars; to these the righteous are compared, Psa 92:13, the Targum is, "the doctors, the mighty preachers, who are like to the strong cedars:'' the words may be rendered, "the boughs thereof cover the goodly cedars", or "cedars of God" (q); that is, overrun and overtop the goodly cedars; alluding to vines running and growing upon high and goodly trees; and so may denote, as before, the power of Israel over the princes and potentates of the earth, comparable to cedars, the most excellent; as things most excellent have often the name of God added to them; see Psa 104:16. (p) "Bacchus amat colles----" Virgil Georgic. l. 2. v. 113. (q) "rami ejus cedros Dei", Tigurine version; so Sept. "et ramia ejus cedri Dei", Musculus, Cocceius; "palmitibus ejus cedri altissimae operiebantur", Piscator, De Dieu; "ramis ejus opertae sunt cedri Dei", 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.