V.1-11 Here Israel meets its first difficulty under Saul. God still loves His people, though they have rejected Him, and here He gives power to Saul and the people to win a mighty victory over their enemies the Ammonites. We notice that God gives Israel an easy test first, there was a total victory (v. 11). But the harder tests were to come later.
V.12-15 You may remember the place “Gilgal” when Joshua was leading the army in taking the land (Joshua 5). That place became the starting place for their victories. Now we see that at this very same place they make Saul their first king. In spite of their self-will in wanting a king, the Lord here gives them the opportunity to make a fresh start under a king.