They would melt, as if thoroughly burned by fire. The waters would burn with fire, so that your name might be made known to your enemies, so that the nations would be stirred up before your face
Other versions
King James Version
As when the melting fire burneth, the fire causeth the waters to boil, to make thy name known to thine adversaries, that the nations may tremble at thy presence! English Standard Version
as when fire kindles brushwood and the fire causes water to boil--to make your name known to your adversaries, and that the nations might tremble at your presence!New International Version
As when fire sets twigs ablaze and causes water to boil, come down to make your name known to your enemies and cause the nations to quake before you!