Charles Ellicott Commentary 1 Samuel 15:16

"Then Samuel said unto Saul, Stay, and I will tell thee what Jehovah hath said to me this night. And he said unto him, Say on." — 1 Samuel 15:16 (ASV)

Stay, and I will tell thee ... — The king was probably turning away, desiring to close an interview which to him was full of bitterness, when he was stopped by the solemn words and probably by the commanding gesture of his old friend and counselor, who now addressed him with the majesty and power of an accredited servant of the Most High.