New Defender's Study Bible Notes
31:37 heaven above. So far as can be ascertained, the heavens are infinite in extent, and so can never be measured by man.
31:37 foundations of the earth. Although the earth’s radius is well established, every human attempt to drill through the earth’s crust to the plastic mantle beneath has, thus far, ended in failure.
31:38 city shall be built. The dimensions of the city in Jerusalem in Jeremiah’s day were much smaller than his description here, and even this city was soon to be destroyed. However, in its modern development, it has indeed reached and exceeded the boundaries described in Jeremiah 31:38-40.