9 So it was, when he had turned his back to go from Samuel, that God gave him another heart; and all those signs came to pass that day. 10 When they came there to the hill, there was a group of prophets to meet him; then the Spirit of God came upon him, and he prophesied among them.
Matthew Henry's Commentary on 1 Samuel 10:9-10
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.