1 Samuel 14:1-3

One day Jonathan, Saul’s son, said to the officer who carried his armor, “Come, let’s go over to the Philistine camp on the other side.” But Jonathan did not tell his father. Saul was sitting under a pomegranate tree at the threshing floor near Gibeah. He had about six hundred men with him. One man was Ahijah who was wearing the holy vest. (Ahijah was a son of Ichabod’s brother Ahitub. Ichabod was the son of Phinehas, the son of Eli, the LORD’s priest in Shiloh.) No one knew Jonathan had left.