When thou didst terrible things which we looked not for, thou camest down, the mountains flowed down at thy presence.
When thou didst. Supply from Isaiah 64:2, As when, etc.
Terrible things - (Psalms 65:5.)
(Which) we looked not for - far exceeding the expectation of any of our nation: unparalleled before (Exodus 34:10; Psalms 68:8).
Thou camest down - on mount Sinai.
The mountains flowed down at thy presence - repeated from Isaiah 64:1; they pray God to do the very same things for Israel now as in former ages. Gesenius, instead of "flowed" here, and "flow" in Isaiah 64:1, translates ( naazoluw (H2151)), with the Septuagint, Chaldaic, Syriac, and Arabic, from a different Hebrew root, 'quake ... quaked;' but "fire" melts and causes to flow, rather than to quake (Isaiah 64:2). The Vulgate supports the English version.