A covenant sign makes the promise visible and memorable. God always gives tangible signs with His covenants — circumcision (Abraham), Sabbath (Israel), bread and wine (new covenant). The rainbow is the sign of this covenant with all creation.
Memory phrase: God gives us signs of His promises.
Talk about it: Why do you think God gave a visible sign for His promise instead of just saying the words?
Prayer: God, thank You for giving us signs that remind us of Your promises.