If the Amalekites be considered, [what] roused them to those arms was — first, indeed — some suspicion and fear, lest (whatever the Israelites might deny) they should occupy their [own] region and kingdom, or at least ravage [their] fields — as Philo says (book 1 On Moses), and, more at length, Josephus (book 3, ch. 2). Then, a certain envy, and [the memory] of the old [injury] which — as they interpreted [it] — Jacob had inflicted on their parent Esau (Genesis 27, v. 36): the memory and vengeance of the injury. For [on] Canticles 2, v. 15, the Targum says: “The impious Amalek came against the sons of Israel, who kept up enmity on account of the birthright taken away, and stole from under the wings of the cloud of glory souls of the tribe of Dan, and slew them.” R. Eliezer (ch. 44) brings forward R. Zacharias saying: “Amalek was the grandson of Esau; and in the old hatred — or [out of] the older enmities of that man — he came upon the Israelites, that from them he might destroy some.”
But if God be considered, he willed by this scourge of the Amalekites to chastise the insolence of the Jews, so often and so causelessly murmuring. Whence the Targum adds, at the cited place: “Then the people was condemned, unless the just should intercede — [they] who are compared to the best spices.” And upon this place of Exodus — by an example, or rather by an allegory of discourse — R. Salomo [Rashi] expounds the whole matter. He says [that] there was a father who bore his little son in his arms before him. But when he saw a lion coming to meet [him], he threw that little son back [onto his back], covered with a pannier-basket. But he also saw a wolf following behind, and therefore began to carry him on [his] shoulders. But this [son], hungry and thirsty, sought food and drink: and the good father furnished both. Behold, meanwhile, [some] travelers, I know not who; and from them that son inquires whether they had anywhere seen his parent. The father hears, and is grieved [that] he — [who] up to this point [was] not acknowledged for [his] kindnesses, and who was present not with body only, but with care and love more than fatherly — is sought as though absent. He is angry, therefore, and casts him to the serpent to be devoured. So indeed, when Pharaoh, like a lion, roared, the Red Sea, like a wolf[‘s] jaws…
(col. 65)
…[the Red Sea, like a wolf’s] jaws, would gape open, [and] the Israelites demanded food and drink, [yet] “God ever protected the sons of Israel — [with] manna, and from the rock gave them water. Yet they said, in the same ch. 17, v. 7: ‘Is God among us, or not?’ Now, therefore, he permits Amalek to bite and wound them, as [with] a serpent.” Something similar R. Phinees teaches, in R. Eliezer (ch. 44), where he also employs another allegory, by which it is shown why, after the forty years of the desert, Moses did not expressly say [that] the Israelites should remember that murmuring of theirs — “Is the Lord among us, or not?” (Exodus 17, v. 7) — but only [that] they should remember the affair of Amalek: because the cause of this [war], namely, had been that querulous speech. Lyranus [Nicholas of Lyra] adds also [that] God willed, by the victory obtained, to add courage to the Israelites, lest they ever be broken by any fear of onrushing enemies, but [that] they should place [their] hope in him, and flee to him, and, in fine, await salvation from him. I add [for my part] that — lest by idleness or too much sloth they grow torpid, and also nourish the vices and seditions which are wont to be born from these — he willed to instill in them somewhat of cares and of dread. For the best prop of a mind [given] to dissolution and to slipping into sins is occupation and fear. There was also to be given an occasion for the excellent apprenticeship of Joshua, and — [for] the [prophetic] figures, about which afterward — the material.