From the early Church Fathers to now.
“And when Moses lifted up his hands, Israel overcame: but if he let them down a little, Amalec overcame.”
“For in this way, when the eyes are lifted up through thought and contemplation and the hands are lifted up in deeds which lift up and exalt the soul, as Moses lifted up his hands, one may consequently say, "The lifting up of my hands is as the evening sacrifice." In this way the Amalekites and all the unseen enemies will be worsted, and the Israelite reasonings in us will prevail.”
“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.”
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.