Charles Ellicott Commentary Genesis 19:30

"And Lot went up out of Zoar, and dwelt in the mountain, and his two daughters with him; for he feared to dwell in Zoar: and he dwelt in a cave, he and his two daughters." — Genesis 19:30 (ASV)

He feared to dwell in Zoar. —Though this little place had been granted to him as an asylum, yet, terrified at the sight of the smoking valley and remembering that he had originally been commanded to go to the mountains, he summons up his courage and proceeds there. The limestone regions of Palestine are full of caverns; and the patriarch, whose wealth had been so great that he and Abraham could not dwell together, is now content to seek in one of these caverns a miserable home.