1 Samuel 13:5-6

5Now the Philistines gathered to fight against Israel, 30,000 chariots and 6,000 horsemen, and troops in multitude, like sand on the seashore. They came up and camped at Michmash, east of Beth-aven.

6When the men of Israel saw that they were in a tight situation (for their troops were hard-pressed), they hid in caves, in thickets, in cellars, and in [dry] cisterns (pits).