Charles Spurgeon Commentary Isaiah 64:1-2

"Oh that thou wouldest rend the heavens, that thou wouldest come down, that the mountains might quake at thy presence, as when fire kindleth the brushwood, [and] the fire causeth the waters to boil; to make thy name known to thine adversaries, that the nations may tremble at thy presence!" — Isaiah 64:1-2 (ASV)

Or, much better, "as when the brushwood burns"; for if God only comes to his people, they are ready to catch the flame, like the dry heather which is soon ablaze; and his enemies also shall be like brushwood before the fire.