The chapter opens with the Israelites in the Wilderness of Sin, where they lament their past in Egypt and express their hunger-driven frustrations to Moses and Aaron. In response to their complaints, God promises to rain down bread from heaven, introducing the miraculous manna. Each morning, the Israelites find this flaky, dew-covered substance on the ground, and they're given specific gathering instructions, with a double portion to be collected the day before the Sabbath. However, some disobey, trying to hoard the manna, only to find it rotten the next day. On the Sabbath, the stored manna remains fresh. This divine provision becomes a daily routine for the Israelites for the next forty years. Towards the chapter's end, Moses and Aaron instruct that a pot of manna be kept as a testament to God's provision.

As the Israelites continue their journey, they face water scarcity at Rephidim, leading to another round of complaints and contention with Moses. In desperation, Moses cries out to God, who instructs him to strike a rock with his staff. Upon doing so, water miraculously flows out, providing for the people. This location is subsequently named Massah and Meribah, referencing the testing and quarreling of the Israelites. The chapter then shifts to a military challenge when the Amalekites attack. Joshua is chosen to lead the defense, and as the battle rages on, it's observed that when Moses holds up his hands, Israel prevails, but when he lowers them, Amalek gains the upper hand. Aaron and Hur support Moses' hands, ensuring they stay raised, leading to Israel's victory. Following this, Moses builds an altar, naming it "The Lord is My Banner."

Jethro, Moses' father-in-law, arrives at the Israelite camp, bringing with him Moses' wife, Zipporah, and their two sons. Moses warmly receives Jethro and recounts to him all that God has done to deliver the Israelites from Egypt. Jethro rejoices, offers sacrifices to God, and dines with the elders. The next day, Jethro observes Moses' laborious task of judging the people's disputes from morning till evening. Concerned, Jethro advises Moses to delegate these responsibilities to capable men who can handle minor issues, allowing Moses to focus on significant matters and seek God's directives. He suggests a hierarchical system where leaders are appointed over thousands, hundreds, fifties, and tens. Moses heeds this advice, establishing a more efficient and manageable judicial system, after which Jethro departs for his own land.