Repetitive creation

Reading through Genesis 1 the repetition is striking. For each of the six days text repeats the phrases:

And God said, “Let .....” And it was so. ..... And God saw that it was good. And there was evening and there was morning, the .... day.

What might we learn from this repetition? God's spoken Word has authority. God's creation is good. The creation is orderly and purposeful. Unlike Babylonian "creation" myths, the creation of YHWH was not an accident which resulted from random actions of fickle gods. Rather is was part of a purposeful plan of a purposeful God.

As an aside, it is interesting to see the English Standard Version has footnote on "let us make man in our image"
Genesis 1:26 The Hebrew word for man (adam) is the generic term for mankind and becomes the proper name Adam
  

Creation of the sun and moon, Raphael (1516)