Where in the Bible does it say that clouds are the only place/thing that rain comes from?
Who covereth the heaven with clouds, who prepareth rain for the earth, who maketh grass to grow upon the mountains.
(Psalm 147:8)
identically, He covers the firmament with clouds.
which is, the clouds are above the firmament.
the clouds, being made of water, which are separated from the seas by an empty space, i.e. "firmament"
the water above.
not to be confused with "the firmament of the heavens" -- another firmament, or empty space, also called "the heavens" - in which the stars, sun, moon and planets are set.