Two crises at Rephidim. The people quarrel over water until Moses says they are nearly ready to stone him, and the place is named for the argument — Massah and Meribah, testing and quarrelling — because of the question they asked: is the LORD among us, or not. Then Amalek attacks, and Israel fights for the first time, with Joshua entering the Bible mid-sentence and unintroduced. The chapter closes with the first command in scripture to write something down, issued in the one region where the earliest alphabetic writing has actually been found.