1 Samuel 22:1

The cave Adullam. — The great valley of Elah forms the highway from Philistia to Hebron. In one especially of the tributary vales or ravines of the Elah valley are many natural caves, some of great extent, roomy and dry, which are still used by the shepherds as dwelling-places, and as refuges for their flocks and herds. David chose one of these natural fastnesses as the temporary home for himself and his followers. The traveller sees that there was ample room for the 400 refugees who gathered under David’s skilled leadership. Stanley even speaks of this Adullam Cavern as “a subterranean palace, with vast columnar halls and arched chambers.”

The name Adullam was probably given to the largest of these great caverns from its proximity to the old royal Canaanitish city of Adullam (Joshua 15:35), ruins of which on a rounded hill to the south of the cave are still visible.

His brethren and all his father’s house. — They of course soon felt the weight of Saul’s anger against the prominent hero of their race, and dreading the fate which often overwhelms whole families for the faults of one of the more distinguished members, fled from their homes, and joined David and his armed force of outlaws.