In Exodus Chapter 17, the Israelites, journeying through the wilderness after their exodus from Egypt, face two significant challenges. First, they arrive at Rephidim and complain to Moses about the lack of water. God instructs Moses to strike a rock at Horeb with his staff, and water miraculously flows from it, quenching the people's thirst. This event demonstrates God's provision despite their grumbling. Second, the Amalekites attack the Israelites. Moses appoints Joshua to lead the fight, while he stands on a hill with Aaron and Hur, holding up his staff. When Moses' hands are raised, Israel prevails; when they drop, Amalek gains the upper hand. Aaron and Hur support Moses' arms until sunset, ensuring victory for Israel. God then commands Moses to record this event and promises to blot out the memory of Amalek. The chapter ends with Moses building an altar called "The Lord is My Banner," symbolizing God's presence and triumph.