Consider; God spoke “let them bring forth” as three phases of Creation. Here again, we see His working is intricately detailed and extremely progressive.
3rd Bring Forth:  in Genesis 1:24 it’s “yatsa’” (yaw-tsaw’) here God literally speaks all creatures set to inhabit the earth into existence; then commanded them to be fruitful and begin to procreate.
It signifies God said let a wriggling and swarming begin to abound; let breeding take place and bring forth abundant increase.
It actually signifies God commanded the animals to “let there be a going after and unto that brings out of and causes a brand new appearing to be seen.” Thus, for the first time since prehistoric earth’s days; God causes begetting as the reproductive union between mammals to be experienced again in the earth.

The ordered concept of “bring forth” defines three different processes; changing from plant life; to all life occupying the waters and air; unto the myriad of creature’s He brought to life and unto an occupying of the earth.
God Made:   so “asah” in the 5th and 6th day of creation became even more intense; for God saw fit to give every living creature an ability unseen before; to go and now begin to bear of itself; after its kind.
The revelatory concept here is the ability to turn about and cause a reproducing in and by others like us of the very same kind; type, and quality of life in God; only experienced in this 5th degree of His ordered change.
Understand this intensity of “God asah’d” in the 5th and 6th day of creation also made every living creature liable to be viable!
“God asah’d” or transformed is also definitive of producing by a determined non-stop moving; by giving all it takes for an accomplishing. “God asah’d” is likened unto a powerful spiritual dynamo so well made; it would literally take an act of God to stop it from working on and on and on!