Amalek came and fought with Israel in Rephidim shortly after the deliverance at the Red Sea. Moses directed Joshua to choose men and engage the enemy while he stood on the hill with the rod of God in his hand. When Moses held up his hands Israel prevailed, but when his hands grew heavy and lowered, Amalek prevailed until Aaron and Hur supported them until sunset. Joshua then defeated Amalek with the edge of the sword. The Lord instructed Moses to write the event as a memorial in the book and recount it to Joshua, declaring that He would utterly blot out the remembrance of Amalek from under heaven. Moses built an altar and declared that the Lord would have war with Amalek from generation to generation. This surprise attack on the stragglers at the rear of the line formed the first encounter with inhabitants of the land after the crossing of the Red Sea. The Lord used the episode to reveal His name as banner while preparing Israel for the journey ahead. The same account later shows God commanding the complete destruction of Amalek through Saul, who failed to obey fully by sparing Agag and the best livestock. Centuries afterward an Agagite descendant plotted against the Jews, illustrating the persistent enmity. The narrative presents Amalek as the embodiment of an enemy that attacks the weak and weary without regard for God, an enmity the Lord maintains across generations as part of the preparation for faithful obedience during the days counted to Pentecost.