Jeremiah 31:37
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. 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.
This promise belongs to the message Jeremiah was told to write in a book, together with chapter 30, containing all that had been revealed about the restoration of Israel, immediately after the exchange of letters between Jeremiah and the elders captive in Babylon. It gave the sure promise of the return from Babylonian captivity, stated so plainly that Daniel, studying it in the books more than sixty years later in the first year of Darius the Mede, understood from it the number of the years for accomplishing seventy years in the desolations of Jerusalem.
It declares that God will not cast off all the seed of Israel as a people or nation, even for all that they have done. This is as certain and impossible to reverse as the impossibility of measuring the heaven above or searching out the foundations of the earth beneath. It stands with the continuance of the ordinances of the sun for light by day and the moon and stars for light by night. The promise is joined to God giving His law in the heart and forgiving sin, and Israel's sin and separation from God still brought judgment and bondage despite the favor God had shown them.
The Jews misapplied this assurance as a guarantee of special favor and blessing despite their sins, relying on their natural descent from Abraham for salvation and for continued favor as God's people. The verse does not promise God's favor regardless of conduct, nor does it excuse unrighteousness and iniquity. It does not make ancestry and national status a substitute for righteousness and a basis for salvation. Being worthy of Abraham's name and being his true children requires following his righteous example, doing his works, and bearing good fruit.
If his descendants failed to bear good fruit, God could raise up children to Abraham to take their place. The promise that God would not cast off Israel stands with the preceding promise about the enduring order of creation, but it is conditional on obedience, so Israel could lose its favored standing through wrongdoing. When John preached repentance because the kingdom of heaven was at hand and baptized confessing sinners in the Jordan, the reading of this word stirred the whole nation with intense interest and by the Holy Spirit convicted even self-satisfied Pharisees of sinful practices, so that the honest in heart desired to obtain the blessing of salvation.
The verse warns God's people in every age, including commandment-keeping people near the close of time, not to presume that divine favor will remain when righteousness gives way to evil. Presuming on divine favor leads to pride and self-reliance, while confession and sincere repentance bring renewal. Persistent refusal to recognize sin leads to spiritual blindness and hardness of heart.