The rainbow of God's PROMISE

 

Q: What was the first thing Noah did after flood?

A:  The first thing Noah did after leaving the ark was build an altar offer sacrifices to God

Q:  What  was God's promise to Noah?

A: God promised Noah that He would never again destroy all life on  Earth with a flood, that natural Earth like cycles like planting and harvest would continue and gave the rainbow as a permanent sign of this covenant.