Sun and Light. The creating activity of this day is curious, at least from a modern perspective. First God created light. Only later did he create the sun. We would think that the order should be reversed or that the two events should be simultaneous.
Light comes from a sun.
This is evidence that the creation story was not designed to be a science textbook. The writer had other intentions. He created a somewhat artificial sequence that highlights the order of God at the expense of technical precision.