God said (occurs 10 times in Introduction). This begins each day: 3rd day twice; 6th day four times. The second act is also of God (1Pe_1:23-25). App-5.
be light = become light (as in Gen_1:2), not the verb "to be". Light not located till 4th day.
was = became, as in Gen_1:2. It is even so in the New Creation: His Word enters and gives light (Psa_119:130. 2Co_4:6).