I don’t know why, but I have always thought there was power in naming. And here is God, obviously naming light, because he says, “Let there be light.” But he also named day and night. And it points out very specifically that he named them.
A couple of thoughts:
Adam named the animals and Eve. He was following in the tradition, in the footsteps, of God by naming them. He was being in God’s image.
To whom or for whom did God name these things. Did he name them so he could explain them to Adam? Was Adam born with a complete language or did God have to teach him? Did God use his own language, whatever that is (ProtoIndian maybe?), or did he make up the earliest Hebrew and speak to Adam with it?