Genesis 1:11

¹¹ And God said, Let the earth bring forth grass, the herb yielding seed, and the fruit tree yielding fruit after his kind, whose seed is in itself, upon the earth: and it was so.

Spreading themselves

'Spreading themselves on the earth,' as in Genesis 8:17, signifies the internal self operating on the external.

'Scum and filthiness' signify something evil and false.