Samuel delivers the word of the Lord to Saul....today, you will wipe Amalek's memory from the earth. Amalek had attacked israel at Rephidim as they struggled in the Sinai desert. Saul does not keep the commandment of the Lord, but instead, selects the best of the booty. The Lord God has had it with him as king over Israel, and announces that his tearing away the kingdom from Saul and giving it to another. Samuel has to finish the job of killing Agag in Gilgal.