'Thick Cloud' in the Bible

If the thick clouds are full of rain, On the earth they empty themselves; And if a tree doth fall in the south or to the north, The place where the tree falleth, there it is.

Whoso is observing the wind soweth not, And whoso is looking on the thick clouds reapeth not.

While that the sun is not darkened, and the light, And the moon, and the stars, And the thick clouds returned after the rain.