I have set my bow in the cloud and it shall be a sign of the covenant between me and the earth. Genesis 9:13
When the rain stops the rainbow shows it is finished and if you look for the pot of gold at the end of a rainbow you will never find it because the gift is not at the end of the rainbow but the rainbow itself. Its a gift of atmospheric beauty, the colours of the bow, and of God's promise to us to never flood the earth again. That's the treasure to be found in a rainbow and the joy when seeing one.
I love this passage of scripture from Sirach 43:11 Look at the rainbow and praise him who made it: it is exceedingly beautiful in its brightness - it encircles the sky with its glorious arc - the hands of the most high have stretched it out.
A splendid gift