Remember what Amalek did unto thee by the way, when ye were come forth out of Egypt;
Remember what Amalek did ... how he met thee - i:e., stealthily and in hostile encounter. This cold-blooded and dastardly atrocity is not narrated in the previous history (Exodus 17:14). It was an unprovoked outrage on the laws of humanity, as well as a daring defiance of that God who had by so many signs and miraculous deeds shown His interest in and favour toward Israel, (see the notes at 1 Samuel 15:1-35; 1 Samuel 27:8; 1 Samuel 30:1-31.)
This was the gravamen of the malignant attack of the Amalekites. It was, in the circumstances, an act of presumptuous impiety, which it was not consistent with the honour of the Deity to overlook; and therefore, as the punishment was, for wise and important purposes, deferred, it was necessary-for the instruction of the Israelites, who required assurance that in cases of open and daring insult to the majesty of God delay did not imply exemption from punishment-to announce to the Israelites that, when fully settled in their own land, they would be employed as executioners of the divine vengeance in exterminating that inveterately hostile people (see the notes at Exodus 17:14; Exodus 17:16; Numbers 24:20).