After my mum died and while we were planning for her funeral, during one dramatic day after we had left the funeral home, my dad and I saw a giant double rainbow in the sky. I understand that single rainbows are a sign of God's covenant with us. But, can you please tell me what a double rainbow is a sign of? Is there something in the Torah or in any other Jewish writings that provides an understanding of the meaning of a double rainbow?
The Seforno on Bereishis 9:17 understands the double rainbow as a wakeup call for Noach and his family “to [spiritually] wake up on seeing it, and to awaken the people of the generation to repent, to be wise, and to do good.” The Sages in several places caution against staring at the rainbow, based on a mystical understanding of the rainbow's significance.
Taken from jewcology.com