Alan J. Avery-Peck, Mishnah's Division of Agriculture: A History and Theology of Seder Zeraim (Chico: Scholars, 1985) 14.
"Since, when creating the world, God carefully distinguished each and every discrete species of plant, so in planting their fields, Israelites must be careful not to plant different species, which could eradicate the distinction caused by God."
I like this quote because it shows how Genesis 1 fits into the priestly worldview, as well as presents one interpretation of the Torah's rules that create or enforce boundaries.