Exodus 17:8 - 16
NIV - 8 The Amalekites came and attacked the Israelites at Rephidim. 9 Moses said to Joshua, "Choose some of our men and go out to fight the Amalekites. Tomorrow I will stand on top of the hill with the staff of God in my hands.
For follow-up discussion and general commentary on the topic. Comments are sorted chronologically.
Proof that the genealogy outlined in Genesis is vital to understanding all that follows, all the way up to the birth of Jesus.