"Thus saith the LORD; If heaven above can be measured, and the foundations of the earth searched out beneath, I will also cast off all the seed of Israel for all that they have done, saith the LORD." (Jeremiah 31:37)
The people of Israel, in spite of all God had done for them, continually rebelled against Him, even turning to other gods. One might think God would have destroyed them and started again, but He had made a promise first to Abraham, then to Isaac, and then to Jacob, that this nation would be His special people, and He would not break that promise.
In our text God reveals the "conditions" under which He would cast off Israel, but they are such that there is no possibility of their being met.
If heaven above can be measured: Neither Abraham nor Jeremiah could have had any concept of the number of stars or the depth of space. Now, with modern telescopes, we see unthinkable distances and even farther and farther as our technology increases. Estimates of the radius of the universe now stand at around 15-20 billion light years, and no end is in sight.
If the foundations of the earth [can be] searched out beneath: Sometimes scientists claim they know more about the sun than they do the earth. But in reality, only one percent of the earth's radius has been explored. The pressures and temperatures which exist deep inside the earth are unthinkably great, and we don't even know how matter acts under those conditions. The promise to Israel is secure.
Scripture is likewise full of "exceeding great and precious promises" (2 Peter 1:4) made to the believer. Our text indicates God's attitudes toward His promises. We need not worry that He will keep His Word. JDM