Genesis 9:12-16 - Meaning of the Rainbow

When I was young, my family used a sprinkler for double duty. It watered the lawn, and cooled off my brothers and me on hot summer days. When the sun hit the water spray just right, there would be a small rainbow that always fascinated me.

The same thing happens at Niagara or other water falls, with rainbows forming in the mist of cascading water. At Yellowstone National Park, rainbows are seen in the steam from geysers like Old Faithful and Castle Geyser.

“What Causes a Rainbow? The Short Answer:
A rainbow is caused by sunlight and atmospheric conditions. Light enters a water droplet, slowing down and bending as it goes from air to denser water. The light reflects off the inside of the droplet, separating into its component wavelengths--or colors. When light exits the droplet, it makes a rainbow.”
That's the simple explanation from NOAA (National Oceanic and Atmospheric Administration). https://scijinks.gov/rainbow/

In the time of Noah, life on earth became so corrupt that God wiped it clean with a massive flood. Only the animals on the ark, as well as Noah and his family survived.  Afterword, God promised humanity that He would never do that again. 

“12 Then God said, 'I am giving you a sign of my covenant with you and with all living creatures, for all generations to come. 13 I have placed my rainbow in the clouds. It is the sign of my covenant with you and with all the earth. 14 When I send clouds over the earth, the rainbow will appear in the clouds, 15 and I will remember my covenant with you and with all living creatures. Never again will the floodwaters destroy all life. 16 When I see the rainbow in the clouds, I will remember the eternal covenant between God and every living creature on earth.'”
(Genesis 9:12-16, New Living Translation, 2015)

I once childishly thought that God created the rainbow after the Flood, as a special reminder of His promise. But that makes no sense. Given the right conditions, rainbows existed before the flood--around waterfalls and geysers, if no where else.

So what did God mean by "I am giving you a sign... my rainbow in the clouds?"

Rainbows are a reminder that --all other conditions being equal-- God's created order does not change. When water freezes, it turns to ice. When water is heated, it turns to steam. When light is filtered through water droplets, a rainbow can be seen: an apt reminder of God's promise to never send that much rain again. The unchangeable laws of nature reflect the unchangeable character of God. He remains True and Just, Loving and Merciful.

Father in heaven, many things around us change. Some days, some years seem to be in more of a flux than others. So we need even more to hear your promise, "I, the Lord, do not change." (Malachi 3:6) Give us peace, rest, and confidence in the dependability of Your character and Your promises. In Jesus' name, Amen.