The first Biblical reference to a rainbow is in the account of the covenant God made with Noah and his offspring after the Flood survivors came out of the ark. (Ge 9:8-17; Isa 54:9, 10)

Nevertheless, this is the first mention of a rainbow, and if a rainbow had been seen earlier, there would have been no real force in God’s making it an outstanding sign of his covenant. It would have been commonplace, and not a significant marker of a change, of something new.