God Himself has kept Israel from seeing and hearing (understanding and applying) His truth, giving Israel a spirit of slumber to make possible the salvation of the Gentiles. He has determined to call and choose only a limited number from Israel in this age, allowing the rest to remain blinded. With the rest of humanity, they will rise in the second resurrection and have the opportunity for salvation.
Martin G. Collins
Basic Doctrines: The Second Resurrection
Elsewhere, Paul says Israel has zeal for God, but not according to knowledge. God has not cast away His people; He will still save them, but He lets us know why things are the way they are now. He has given them over to being deceived; He has permitted it. God, writes Paul, has given them a spirit of stupor. He permitted it even as He permitted Adam and Eve to be tested in the Garden. These scriptures show that Israel's spiritual diet was misleading them; their table had become a snare. A table is a symbol of where we eat. It is literally where we eat physical food, but spiritually, it refers to our mental and spiritual nourishment. What the Israelites were feeding their minds was distracting them to the degree that they were unable to see the truth when it was presented to them.
John W. Ritenbaugh
Division, Satan, Humility
From the Exodus (c. 1445 BC) until Paul wrote this epistle (c. AD 55), the Israelites had not been offered the Holy Spirit (except for those few God specifically called). The bulk of the people had a form of "blindness," or they were "slumber[ing]," as Paul says. While sleeping, a person does not know what is going on; he is oblivious to what is happening around him. It ought to be easy, then, for us to understand Israel's constant bickering, warring, complaining, sexual sins, intrigues, and murders, remembering that they were operating within a God-imposed, spiritual handicap so that an examplecould be set and written for us to learn from. Humanly, it creates quite a deterrent! God, of course, knew what He was doing all along, putting these people through the paces so that our understanding could be deeper and broader.
John W. Ritenbaugh
Pentecost and the Holy Spirit