(Exodus 17:8) "And Amalek came": This verse is recondite and is explicated by (Iyyov 8:11) "Can the rush grow without swamp? Can grass grow without water?" So, Israel without Torah. And because Israel separated from Torah, therefore, the foe (Amalek) came upon them. For the foe comes only by reason of sin and transgression. Thus, "And Amalek came, etc."