Albert Barnes Commentary 1 Samuel 14:19

"And it came to pass, while Saul talked unto the priest, that the tumult that was in the camp of the Philistines went on and increased: and Saul said unto the priest, Withdraw thy hand." — 1 Samuel 14:19 (ASV)

Withdraw your hand - that is, “Desist from what you are doing.” In his impatience to join the battle, Saul would not wait for the answer from God which he had asked Ahijah to inquire for; just as later, in 1 Samuel 14:35, he would not wait to finish the altar he had begun to build. Had he waited then, he would have doubtless avoided the error into which he fell.