Samuel gave the newly anointed Saul 3 signs, one being that he will enter Gibeath-elohim, where there is a garrison of the Philistines, and immediately meet a group of prophets coming down from the high place with harp, tambourine, flute, and lyre before them, prophesying. Then the Spirit of the LORD will rush upon him, and he will prophesy with them and be turned into another man. God will be with him. (1 Samuel 10:1-7)
When they came to Gibeah, he prophesied with the group of prophets and received the Spirit of the LORD. (1 Samuel 10:8-11)