Exodus 17

The Israelites again complain fiercely, this time about the lack of water at Rephidim, even doubting God's presence, demanding, "Is the Lord among us or not?" God instructs Moses to strike a specific rock at Horeb with his staff. Water immediately gushes out, satisfying the thirst of the entire camp. Shortly after, the Israelites are attacked by the Amalekites. Moses holds his hands up in prayer; when his hands are raised, Israel prevails, but when they drop, the Amalekites gain the advantage. Aaron and Hur help Moses keep his hands raised, securing victory.