What did the Old Testament say God would do if Israel was disobedient?
The Old Testament warned Israel that if they were disobedient, God would chastise them and bring their enemies against them. It did not, however, reveal that a day would come when God would sovereignly, judicially blind the nation spiritually for a long period of time.
Les explains that the Old Testament certainly warned Israel that if they were disobedient, God would chastise them and bring in their enemies, and so on. However, he can think of nowhere in Scripture where God actually told Israel that a day would come when they would be spiritually blinded. This blindness in part has happened to Israel—a sovereign, judicial blinding by God for a long period, now over 1900 years. Les calls this the core of the mystery in Romans 11:25, something nowhere else in Scripture was ever revealed. He also notes a brief preview in Acts 13, where Paul encounters a Jewish sorcerer named Bar-Jesus on the island of Paphos.