The interpretation timeline
Isaiah 19:6 Douay-Rheims

And the rivers shall fail: the streams of the banks shall be diminished, and be dried up. The reed and the bulrush shall wither away.

1105 – 1871 5 witnesses

Scholastic

c. 1100 – 1500
1105
A.D.
Rashi Jewish
1040–1105
“And they shall abandon When the water decreases, the mud is noticeable in it, and it becomes a mire and is abandoned. the deep canals Heb. יְאֹרֵי מָצוֹר. The deep canals, like the ditches of the sieges of cities. [Rashi according to Parshandatha. Printed editions read:] In the ditches of the sieges of cities. reeds and rushes that grew there because of their abundant water. shall be cut off When the canals dry up, the reeds stop growing, and they dry up and fall. Jonathan renders: Shall not come up. Elsewhere (infra 33:9), he renders: “The Lebanon was dried up, cut off (קָמַל),” as ‘fell.’ I say, however, that it is an expression of cutting off, that they are cut off by themselves because of their dryness, and they fall.”
Source
1167
A.D.
Ibn Ezra Jewish
1089–1167
והאזניחו And shall leave.. א is epenthetic. והאזניחו נהרות And the people will leave the rivers. דללו They shall be poor. Comp. דל poor (Lev. 14:21). יאורי מצור The ponds of siege. The ponds which are prepared in order that the enemy should not be able to destroy the inhabitants through want of water, when he besieges the town. קנה וסוף The reeds and flags. The plants on the banks of the river. קמלו Shall be cut off. Another instance of the same root occurs in this book (33:9)”
Source
1256
A.D.
Thomas Aquinas Catholic
1225–1274
“The burden of Egypt. In this part he threatens the destruction of the Egyptians, following out its manner and order; and it is divided into three parts: first, the preparation of the punishment is described; in the second, the destruction itself, at "and I will deliver Egypt"; in the third, the resulting benefit, at "in that day there shall be five cities." Now the preparation of the punishment is described as to four things. First, as to the disposition of the enemies: "he shall ascend" — by inspiring — "upon a cloud," from which comes the storm; "light," on account of agility and readiness: Ps. 96: "cloud and darkness are round about him." Second, as to the stupefaction of the ruling gods. "And they shall be moved": because they were broken by the Assyrians; or because they were not able to give an answer; or because they did not even appear to man on that same day. Ez. 6: "they shall be broken," etc. "The heart of Egypt," that is, the king and the princes, from whom all the vigor of Egypt comes. Above, 1: "every head is languishing, and every heart sad." Third, as to the dissension of those resisting: as to outward engagement, "to clash"; as to strangers, "the Egyptians"; as to kinsmen, "man shall fight"; as to acquaintances and friends, "and man against his friend"; as to different peoples, "city." He sets down the diversity of wills: "it shall be broken up," that is, divided, "the spirit," that is, the will, "in its bowels," that is, in the inhabitants of the land. Matt. 12: "every kingdom divided against itself shall be made desolate." Fourth, as to the error of men taking counsel: "and the counsel." Job 5: "he catches the wise in their own craftiness, and scatters the counsel of the wicked" — and of the demons: "and they shall inquire" — in vain. Above, 8: "and when they shall say to you: seek unto pythons, and unto wizards who mutter in their enchantments," etc. Note, concerning that word "upon a cloud," that there is a manifold cloud. The first is of the flesh assumed. Job 38: "Where were you when I made a cloud its garment, and wrapped it in darkness as in swaddling clothes of infancy?" The second is of the virginal womb. 3 Kings 18: "Behold a little cloud arose out of the sea." The third is of the devout mind. Ps. 67: "His magnificence and his power are in the clouds." The fourth is of the seat of judgment. Ps. 96: "Cloud and darkness are round about him; justice and judgment are the preparation of his seat." Also note that from the first cloud proceeds the sacramental or sanctifying rain. John 19: "from the side (of the Lord) immediately came out blood and water." From the second proceeds the food of consolation. Wis. 19: "the cloud overshadowed the camp, and out of the water that was before, dry land appeared." And below: "seeing your wonders and marvels: for like horses they fed on the food." Above, 18: "like a cloud of dew." From the third proceeds the flashing of preaching. Job 37: "the clouds long for the grain, the clouds scatter their light." From the fourth proceeds the storm of damnation. (Jer. 4): "behold as a cloud"; Ps. 67: "his power is in the clouds." Also note, concerning that word "a light cloud," that the first is called light on account of the dignity of its eminence. Daniel 7: "behold, one like the son of man came in the clouds." The second is called light on account of the purity of virginity. Apoc. 14: "and behold a white cloud, and upon the cloud one sitting like to the son of man." The third is called light on account of the swiftness of obedience. Below, 60: "who are these that fly as clouds?" The fourth is called light on account of the ease of its execution. Ecclus. 43: "in his greatness he set the clouds, and the stones of hail were broken." "And I will deliver Egypt." Here he pursues the destruction itself: first, as to the servitude of the people; second, as to the desolation of the land, "and it shall be dried up"; third, as to the stupefaction of the wise men, "the princes are fools." "Of masters" — of the Assyrians, the Chaldeans, the Romans. Deut. 28: "you shall serve your enemy." Now he designates the destruction of the land through the dryness of the waters, in which Egypt is adorned and rich: either because the wrath of God brought it about beforehand that the waters should dry up, and the animals die; or he speaks hyperbolically, as if to say: the tribulation will be so great that it will seem even to dry up the waters. He sets down, therefore, three things. First, the manner of the drought: "it shall be dried up," that is, diminished, "the river" — the Nile — "the streams," the other rivers. Ezechiel 30: "I will make the channels of the rivers dry." Second, he sets down the sign of the drought: "the reed and the bulrush," which are nourished in the waters. Below, 35: "the greenness of the reed and the bulrush shall spring up." Third, he sets down the harm of the drought: "it shall be made bare" — first, of agriculture, "from the fountain," that is, from the beginning; or this refers to the end. Ps. 106: "he turned rivers into a desert, and the outgoings of waters into thirst." Second, of the fishermen: "the fishermen shall mourn." Ezech. 29: "I will cast you into the desert, and all the fish of your river." Third, of the various craftsmen: "they shall be confounded who work in flax," which grows in moist places. "Withering," that is, drying up; "ponds," fish-ponds. "The princes are fools." Here he sets down the stupefaction of men: first, as to error in counsels; second, as to fear in wars, at "in that day." Concerning the first, three things. First he mocks the folly of the wise as to deliberation: "the princes are fools" — that is, the philosophers — "of Tanis," where study flourished: Jer. 51: "every man has become foolish"; as to the promulgation of counsel: "the wise"; as to their own self-commendation: "how will you say to Pharaoh?" That is, how will you be able to say, when he will think that you have counseled badly, this thing which each one of you was accustomed to say for his own commendation, so that his counsel might be believed: "I am the son of the wise" — as if to say, I possess wisdom by inheritance; or "a disciple of the kings" — who of old were philosophers. Job 15: "both the aged and ancient men are among us, much elder than your fathers." Second, he mocks the confidence of the king: "Where now?" And first, the question: below, 47: "let them stand and save you"; second, the answer: "the fools have withered away," that is, have failed, as above; third, he mocks the cowardice of the deceived people: "they have deceived." Here he does three things. First he sets down the deception of the wise: "they have deceived the corner," that is, the kingdom, in which many are joined together as walls at a corner. Below, 47: "your wisdom and your knowledge have deceived you." Second, the permission of God: "the Lord has mingled" — this is often said metaphorically. "A spirit of dizziness," that is, of error, after the manner of one who suffers vertigo. 3 Kings, last chapter: "the Lord has put a lying spirit in the mouth of all your prophets." Third, the error of the people itself: "and to err." "Head" — namely, neither as to the beginning; "tail" — neither as to the end; "bowing down" — as to the old man; "holding back" — as to the young man, who needs restraint, or one given to wantonness. 2 Tim. 3: "but evil men and seducers shall grow worse." "In that day." Here he threatens the fear of the strong. And first he sets down the fear: "as women," weak and feeble. Jer. 51: "their strength is devoured, and they have become as women." Second, the reason: "the land of Judah shall be" — namely, the memory of the evils which they did to them, turning them away from the worship of God, on account of which they shall know that they have incurred the wrath of God. 1 Mach. 6: "now I remember the evils that I did in Jerusalem." "In that day." Here the resulting benefit, or consolation, is set down — namely, their conversion. And first, a threefold sign of the conversion: of which the first is the oath, "swearing." Below, 65: "he who swears," etc., "shall swear by the God, Amen: because the former distresses are delivered to oblivion." "The city of the sun" — Heliopolis. "The language of Canaan" — which borders on the language of the Jews, so that they might also agree in language with the people of God. For among these certain Syrians were transplanted by Nebuchadnezzar, who kept their own language. The second sign is a sacred building: "an altar of the Lord, and a monument" — because they worshiped many gods, as is said in Acts 17. This (some say) was fulfilled in the time of the Maccabees, when, many Jews fleeing into Egypt, Onias, wishing to fulfill this prophecy, built an altar against the precept of the Law, which is against that word of Exod. 20: "you shall not build me an altar," etc.; concerning which it is argued in Dan. 11: "the children also of the transgressors of your people shall lift themselves up to fulfill the vision, and they shall fall." Whence it is clear that this is not the meaning, but rather it concerns an altar to be built for Christian worship. The third sign is that they call upon the help of God: "they shall cry out"; "a savior" — Jesus. Ps. 90: "he cried to me." Second, he sets down the manner of the conversion: first, as to the reception of the faith, "and he shall be known": Jer. 31: "all shall know me, from the least even to the greatest, says the Lord"; second, as to the offering of sacrifices and vows, "and they shall worship": Malachi 1: "in every place there is offered to my name a clean oblation"; third, as to the remission of sins: "and he shall strike" — first, through many punishments; "and he shall heal" — from sin. Job 5: "he wounds and cures; he strikes, and his hands shall heal." Third, he sets down the threefold effect of the conversion: namely, peace: "in that day there shall be a way," which before could not be, on account of the different kingdoms, which at the birth of the Lord were joined together under the Romans. "They shall serve" — in trading with one another; or because Syrian soldiers were in the legions of the Romans for the guarding of Egypt. Above, 2: "nation shall not lift up sword against nation." Second, he promises the second effect, the truth of the faith: "in that day the third" — together, and serving the Romans equally, and in unity of faith. John 10: "there shall be one fold and one shepherd." Rom. 10: "there is no distinction of Jew and Greek." Third, he sets down the third effect, namely the divine blessing: "it shall be" — namely, Israel — "a blessing," because through the apostles the whole world received the blessing of God. "An inheritance," because he was born there, and fulfilled the mysteries of our salvation there. Ps. 113: "he blessed the house of Israel."”

Post-Reformation

c. 1650 – 1900
1771
A.D.
John Gill Reformed
1697–1771
“And they shall turn the rivers far away,.... The river Nile, called "rivers", the plural for the singular, because of the abundance of water in it; or its seven streams, with other rivulets, derived from it. Some make the "they" here to refer to the kings of Egypt, and interpret the words of some projects of theirs, by which the course of the river was turned to great disadvantage; particularly they understand it of the twelve tyrants that reigned after Sethon, to whom they ascribe the digging of the vast lake of Moeris, the two pyramids built in the midst of it, and a labyrinth near it, though only the labyrinth was made by them (b); and as for the lake, it was made by Moeris, a king of Egypt, from whom it had its name, some hundred years before; and, besides, was of service, and not disservice, to the Nile; for it received its waters when it overflowed too much, and it furnished it with water by an outlet when it failed: rather therefore this passage may be illustrated by the attempt which Necus, the son of Psammiticus, whom the Scripture calls Pharaohnecho, made, to join the Nile and the Red Sea together, by making a canal from the one to the other; in which work he lost a hundred and twenty thousand men, and desisted from it without finishing it (c); but it is thought hereby the river was greatly weakened: and the brooks of defence shall be emptied and dried up; as the river of Nile and its streams were the defence of the land of Egypt, as well as made for the fruitfulness of it, for these must make it less accessible to a foreign enemy; and besides, here lay their shipping, which were their protection; and moreover, from hence brooks and courses of water might be derived and carried about their fortified cities, which added to the strength of them. The Targum renders it deep brooks or rivers; and Kimchi interprets it the brooks of Egypt, taking Matzor to signify Egypt, a word in sound near to Mitzraim, the common word used for Egypt. It looks, by this and other expressions in the context, as if more were designed than the above instance or instances will account for: the reeds and flags shall wither; which grew in the brooks, and near them; and therefore much more the grass and corn, and other trees, which were at a distance; besides, these are mentioned, bemuse of the great usefulness they were of; for of these they made ships, barks, and boats, and mats for bedding, and nets fishing; as also paper to write on, as follows, and which was a staple commodity with them; See Gill on Isa 18:2. (b) Herodot. l. 2. c. 148, 149. (c) Ib. c. 158.”
Source
1871
A.D.
1871
“they shall turn the rivers--rather, "the streams shall become putrid"; that is, the artificial streams made for irrigation shall become stagnant and offensive when the waters fail [MAURER]. HORSLEY, with the Septuagint, translates, "And waters from the sea shall be drunk"; by the failure of the river water they shall be reduced to sea water. brooks of defence--rather, "canals of Egypt"; "canals," literally, "Niles," Nile canals, the plural of the Egyptian term for the great river. The same Hebrew word, Matzor, whence comes Mitzraim, expresses Egypt, and a place of "defense." HORSLEY, as English Version translates it, "embanked canals," reeds . . . flags--the papyrus. "Reed and rush"; utter withering.”
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.