Summary: God’s thoughts are above ours, unattainable, but He has made them available to us.
My ways, My thoughts, My words
Isaiah might be one of the great geniuses of history. He did not take the trouble to define and systematize all he knew, but his observations were way ahead of their time. It is easy to overlook, since many of the scientific ideas we take for granted have been around for centuries or at least decades. But that is all, they have not been around for millennia.
In the late 1700s when Antoine Lavoisier discussed the principles of evaporation in his landmark book, The Elements of Chemistry, he did not take credit for discovery of the process. He described the process, but discussed it as a law of nature, something already known. Isaiah knew it. He knew it on such a grand scale that in a very concise way describes several scientific ideas:
Levoisier’s description of evaporation: Isaiah shows that water returns to the heavens where it prepares to come to earth again.
Newton’s law of conservation: Isaiah showed how the use of water does not destroy it, but eventually, after accomplishing a complex purpose, recycles it back into the clouds.
Clapham’s conception of the ecosystem: Isaiah shows how the physics and chemistry of water are related to plant biology and the symbiosis of the food chain.
We might think that everyone knows these things, but the exact interaction of these different processes were not yet known to everyone in 800 BC. That’s why so many people worshiped gods of water and sky and fertility. Isaiah believed in one God who was in charge of all these processes, but he also saw them as natural predictable systems that had their own mechanics and laws.
Not only is Isaiah a scientific thinker ahead of his time, but he is a poet comparable to the greatest poets in history. He is not content to say that God’s word is like the rain, He goes to great lengths to show what he means by this statement. His use of extended metaphor in this passage rivals Homer’s who was using similar devices in The Illiad and The Odyssey around the same time in Greece.
I am somewhat biased, but I will go so far to say that Isaiah does it better than Homer.
Isaiah does something even more impressive with this passage. He combines his observations of the natural world with poetry to paint a beautiful picture of weather, crops and food. Then he uses the whole thing to a higher spiritual purpose. He describes the working of God and compares His thinking to ours.
God’s thoughts are not our thoughts
Isaiah is not content to show that they are fundamentally different, but that God’s thoughts are unreachably superior.
Where are the heavens? Can we reach them?
It is difficult to say. If we take an elevator to the top of the Sears tower, or climb a mountain we may find ourselves engulfed by clouds. Have we reached the heavens? We still have a fundamental attachment to the earth. We feel the height we have reached, but we are aware that there is much more above us.
If we fly in an airplane or a jet, we may find ourselves above the clouds with nothing but blue sky above us on an overcast day. Have we reached the heavens? We are sometimes frighteningly aware that we still have a fundamental attachment to the earth. We may not have bedrock under our feet, but gravity still tugs at us and turbulence reminds us that it is a long way down, but we would reach it faster than we want to.