This is a vexing passage that has engendered incredible and valuable debate over the millennia. It is perhaps not surprising (?) that today’s Revised Common Lectionary skips this passage. The Epistle today is Romans 11:1-2a, 29-32. How convenient. But Romans 11:26a deserves a thorough treatment.
Fortunately, my excellent friend and even better scholar Richard Wright has an excellent short paper summarizing the arguments around this verse. He incorporates all (then) current debate and comes to perhaps a surprising conclusion. It should be read.