1 Samuel 24:3

24:3 He came to the sheepfolds by the road, where there was a cave. Saul went into it to relieve himself. ¹ 

Now David and his men were sitting in the recesses of the cave.

¹ tn Heb “to cover his feet,” an idiom (euphemism) for relieving oneself (cf. NAB “to ease nature”).