John Gill Bible Commentary

How he met thee by the way,.... Not with necessary provisions, food and drink, which would have been but a piece of kindness and humanity to travellers; but met them sword in hand, in order to stop their journey, and make them captives, at least to harass and distress them: and smote the hindmost of thee; came upon them in a sly cowardly manner, and attacked their rear: even all that were feeble behind thee: women and children, and such men as were weak, sickly, labouring under some disorder, and so lagged behind, and could not keep up with the rest; on these Amalek first fell, and began his attack here: when thou wast faint and weary; with travelling, and the more so for want of water, which was their case at Rephidim, when Amalek came out against them; which is another aggravation of their unkind usage of them they were not to forget: and he feared not God; who was then in the pillar of cloud and fire with Israel, which phenomenon Amalek might see, and yet did not fear; and who had done such wonders for Israel in Egypt, and had brought them from thence, and had drowned Pharaoh and his host in the Red sea, of which doubtless Amalek had heard, and yet feared not the Lord, who had done such great things.