Albert Barnes Commentary 1 Samuel 9:16

"To-morrow about this time I will send thee a man out of the land of Benjamin, and thou shalt anoint him to be prince over my people Israel; and he shall save my people out of the hand of the Philistines: for I have looked upon my people, because their cry is come unto me." — 1 Samuel 9:16 (ASV)

That he may save my people out of the hand of the Philistines... — These words are not easily reconcilable with 1 Samuel 7:13.

It is possible that the aggressive movements of the Philistines, after the long cessation of conflict mentioned in 1 Samuel 7:13, coupled with Samuel’s old age and consequent inability to lead them to victory as before, were among the chief causes that led to the cry for a king. If this were so, the Philistine oppression alluded to in this verse might, in a general survey, be more connected with Saul’s times than with Samuel’s.