Luke 23:30 - Ellicott's Commentary On The Whole Bible

Then shall they begin to say to the mountains. — The imagery was natural in a limestone country such as Judæa, subject to earthquakes. Commonly, such catastrophes were dreaded, and men prayed against them. The time was coming when the dens and caves which usually offered a place of refuge from invading armies (Isaiah 2:19) would prove insufficient, and men would cry, as they had done of old (comp. Hosea 10:8, from which the words are quoted), to the mountains to fall on them.