I Samuel 14:1-3

Now it happened one day that Jonathan the son of Saul said to the young man who bore his armor, “Come, let us go over to the Philistines’ garrison that is on the other side.” But he did not tell his father. And Saul was sitting in the outskirts of Gibeah under a pomegranate tree which is in Migron. The people who were with him were about six hundred men. Ahijah the son of Ahitub, Ichabod’s brother, the son of Phinehas, the son of Eli, the LORD’s priest in Shiloh, was wearing an ephod. But the people did not know that Jonathan had gone.