The interpretation timeline
Exodus 17:11 Douay-Rheims

And when Moses lifted up his hands, Israel overcame: but if he let them down a little, Amalec overcame.

A.D. 45 – 1849 7 witnesses

Patristic

before A.D. 750
45
A.D.
c. 15 B.C.–A.D. 45
“LXVI. And the war between these things is manifest. At all events, according to the superiority of the mind when it applies itself to incorporeal objects, which are perceptible only to the intellect, passion is put to flight. And, on the other hand, when this latter gains a shameful victory, the Philo here supposed that vttvoq, sleep, is derived from vipiaiq, relaxation, or from v$ir]fii, to relax. mind yields, being hindered from giving its attention to itself and to all its actions. At all events, he says in another place, " When Moses lifted up his hands Israel prevailed, and when he let them down Amalek prevailed." And this statement implies, that when the mind raises itself up from mortal affairs and is elevated on high, it is very vigorous because it beholds God ; and the mind here means Israel. But when it relaxes its vigour and becomes powerless, then immediately the passions will prevail, that is to say, Amalek ; which name, being interpreted, means, the people licking. For he does, of a verity, devour the whole soul, and licks it up, leaving no seed behind, nor anything which can excite virtue ; in reference to which it is said, "Amalek is the beginning of nations ; 't because passion governs, and is the absolute lord of nations, all mingled and confused and jumbled in disorder, without any settled plan ; and, through passion, all the war of the soul is fanned and kept alive. For God makes a promise to the same minds to which he grants peace, that he will efface the memorial of Amalek from all the lands beneath the heaven.”
Source
389
A.D.
A.D. 329–390
“For my own warfare, however, I am at a loss what course to pursue, what alliance, what word of wisdom, what grace to devise, with what panoply to arm myself against the wiles of the wicked one. What Moses did is to conquer him by stretching out his hands upon the mount, in order that the cross, thus typified and prefigured, may prevail.”
Source

Scholastic

c. 1100 – 1500
1105
A.D.
Rashi Jewish
1040–1105
כאשר ירים משה ידו WHEN MOSES LIFTED UP HIS HAND — But could Moses’ hands win the battle etc.? See the whole passage as it is given in the Treatise Rosh Hashanah 29a.”
1270
A.D.
Ramban Jewish
1194–1270
“AND WHEN HE LET DOWN HIS HAND, AMALEK PREVAILED. By way of the plain meaning of Scripture, when Moses was compelled to lower his hands because of weariness, he saw that Amalek prevailed. He then commanded Aaron and Hur to support them, and thus he would not lower them again. Our Rabbis have said in the Midrash: “Did Moses cause Amalek to prevail over Israel? It was merely because a person is forbidden to tarry three hours with his hands spread heavenward.””
Source

Post-Reformation

c. 1650 – 1900
1771
A.D.
John Gill Reformed
1697–1771
“And it came to pass, when Moses held up his hand, that Israel prevailed,.... With his rod in it as a banner displayed, as some think, which inspired the Israelites with courage to fight, and they had the better of it; though Aben Ezra rejects that notion, observing, that if that had been the case, Aaron or Hur would have lifted it up, or fixed it in a high place on the mount, that it might have been seen standing; and therefore he thinks the sense of the ancients the most correct, that it was a prayer gesture. And among the Heathens, Moses was famous for the efficacy of his prayers; Numenius, the Pythagoric philosopher (y), says of him, that he was a man very powerful in prayer with God: and so all the Targums interpret it, and particularly the Targums of Jonathan and Jerusalem paraphrase the words,"when Moses lift up his hands in prayer, the house of Israel prevailed, but when he restrained his hands from prayer, the house of Amalek prevailed,''as it follows: when he let down his hand, Amalek prevailed; so that victory seemed to go sometimes on one side, and sometimes on the other, according as the hand of Moses, with the rod in it, was held up or let down; when it was held up, and Israel saw it, they fought valiantly, but when it was let down, and they could not see it, their hearts failed them, and they feared it portended ill to them, which caused them to give way to the enemy. The spiritual Israel of God are engaged in a warfare with spiritual enemies, some within, and some without; and sometimes they prevail over their enemies, and sometimes their enemies prevail over them for a while; and things go on very much as a man either keeps up or leaves off praying, which is signified by the lifting up of holy hands without wrath and doubting, Ti1 2:8 and which when rightly performed, under the influence of the divine Spirit in faith, in sincerity, and with fervency and constancy, has great power with God and Christ, and against Satan and every spiritual enemy. (y) Apud Euseb. Praepar, Evangel. l. 9. c. 8. p. 411.”
Source
1832
A.D.
Adam Clarke Methodist
1762–1832
“When Moses held up his hand - We cannot understand this transaction in any literal way; for the lifting up or letting down the hands of Moses could not, humanly speaking, influence the battle. It is likely that he held up the rod of God in his hand, Exo 17:9, as an ensign to the people. We have already seen that in prayer the hands were generally lifted up and spread out, (See Clarke's note on Exo 9:29), and therefore it is likely that by this act prayer and supplication are intended. The Jerusalem Targum says, "When Moses held up his hands in prayer, the house of Israel prevailed; and when he let down his hands from prayer, the house of Amalek prevailed." We may therefore conclude, that by holding up the hands in this case these two things were intended: 1. That hereby a reference was made to God, as the source whence all help and protection must come, and that on him alone they must depend. 2. That prayer and supplication to God are essentially necessary to their prevalence over all their enemies. It is indisputably true that, while the hands are stretched out, that is, while the soul exerts itself in prayer and supplication to God, we are sure to conquer our spiritual adversaries; but if our hands become heavy - if we restrain prayer before God, Amalek will prevail - every spiritual foe, every internal corruption, will gain ground. Several of the fathers consider Moses, with his stretched-out hands, as a figure of Christ on the cross, suffering for mankind, and getting a complete victory over sin and Satan.”
Source
1849
A.D.
1774–1849
“And when Moses lifted up his hands. Here Moses was a figure of Christ on the cross, by whose power and mediation we overcome our spiritual enemies. (Challoner) — Hands, forming the sign of the cross, as the fathers observe, in the posture of a suppliant. St. Jerome says, the people fasted also till the evening. (contra Jos. ii.) (Calmet) — If heretics deride the priests of God, standing with their hands extended at the altar, let them reflect on Moses, and on Jesus Christ, who, lifting up his hands, blessed his disciples; and hence learn, that such ceremonies are not vain. (Worthington)”
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.