Genesis 1:3

³ And God said, Let there be light: and there was light.

Genesis 9:5

⁵ And surely your blood of your lives will I require; at the hand of every beast will I require it, and at the hand of man; at the hand of every man's brother will I require the life of man.

'Heat of the sun,' as mentioned in Revelation 7:16, signifies lust to do evil.