Isaiah 64:3
When thou didst terrible things which we looked not for, thou camest down, the mountains flowed down at thy presence.
When thou didst terrible things, which we looked not for, thou camest down,.... Referring to the wonderful things God did in Egypt, at the Red sea, and in the wilderness, and particularly at Mount Sinai, things that were unexpected, and not looked for; then the Lord came down, and made visible displays of his power and presence, especially on Mount Sinai; see Exodus 19:18:
the mountains flowed down at thy presence; not Sinai only, but others also; Kimchi says Seir and Paran; Judges 5:4.