Interesting observation: only days one and three have God saying something and it becoming. Creating by fiat. Every other day describes God making or creating the things He orders into existence. The light simply “is” when God commands. And here on day three the waters gather and dry land appears at His command. Likewise, the earth “brings forth” vegetation at His word. Perhaps there is some profound meaning in God making the expanse, the celestial bodies, the animals, and humanity, while the light, sky, land and vegetation come into existence at his word. It does say a lot about God’s sovereignty. He speaks and creation is. But it also says a lot about His artistry that He took the trouble to make, to shape, to design His oeuvre.
There are also a couple of important ideas introduced on this day of creation. Two key terms stand out:
Seed. Seeds are a big deal on day three. As a noun or verb (translated yield) fully one fifth of the words in verses 11-13 are the word seed. (I can geek out about such stuff.) But this isn’t just about day three involving plants. The idea of seeds or offspring or generations goes on to be an important theological theme of Genesis and the whole Gospel story. Life is about propagation. It is sort of an imperative in creation.
Kind. Another important word for this passage is introduced and repeated here in day three. The plants are created according to categories. This idea will be seen again on day six with the animals. God created order and there is a certain goodness to the structure of creation. The opposite of that good order is evil and is expressed in chaos or confusion.
If we want to go on a bit of a tangent here, this is where evolution is addressed. And we have to be careful about what we mean with that. What we see here in Genesis is that God creates life in categories right from the beginning. Even if we want to allow for “intelligent design” there does not seem to be room here for all the variety of plant life (and later animal life) to have been “developed” through natural selection run amok. What we aren’t seeing here is a denial of natural selection as a process for the preservation of the kinds, the species. Natural selection is a fact. It is observable. It just didn’t lead to one kind producing another kind.