11 And it came to pass, when all that knew him beforetime saw that, behold, he prophesied with the prophets, then the people said one to another, What is this that is come unto the son of Kish? Is Saul also among the prophets?

Matthew Henry's Commentary on 1 Samuel 10:11

Commentary on 1 Samuel 10:9-16

(Read 1 Samuel 10:9-16)

The signs Samuel had given Saul, came to pass punctually; he found that God had given him another heart, another disposition of mind. Yet let not an outward show of devotion, and a sudden change for the present, be too much relied on; Saul among the prophets was Saul still. His being anointed was kept private. He leaves it to God to carry on his own work by Samuel, and sits still, to see how the matter will fall.