1 Samuel 14:17-21

Then said Saul unto the people that were with him, Number now, and see who is gone from us. And when they had numbered, behold, Jonathan and his armourbearer were not there.

And Saul said unto Ahiah, Bring hither the ark of God. For the ark of God was at that time with the children of Israel.

And it came to pass, while Saul talked unto the priest, that the noise that was in the host of the Philistines went on and increased: and Saul said unto the priest, Withdraw thine hand.

And Saul and all the people that were with him assembled themselves, and they came to the battle: and, behold, every man’s sword was against his fellow, and there was a very great discomfiture.

Moreover the Hebrews that were with the Philistines before that time, which went up with them into the camp from the country round about, even they also turned to be with the Israelites that were with Saul and Jonathan.