(Exodus 17:1) "And the entire congregation of the children of Israel journeyed from the desert of Sin … and they encamped in Refidim": (homiletically,) "rafu yadam" ("their hands weakened") in words of Torah. And because Israel grew lax in Torah, Amalek attacked them (viz. 17:8), for the foe comes only as the result of sin and transgression.