Caves were Used as Resting Places
Source: TTT
1 Samuel 24:3
Soon Saul came to the sheepfolds along the road, where there was a cave, and he went in to relieve himself. And David and his men were hiding in the recesses of the cave.
1 Kings 19:9
There Elijah entered a cave and spent the night. And the word of the LORD came to him, saying, “What are you doing here, Elijah?”