Well; because of unbelief they were broken off, and you stand by faith. Be not arrogant, but fear:
All Commentaries on Romans 11:20 Go To Romans 11
Ambrosiaster
AD 400
You ought to thank God for his gift in Christ and not insult them but rather pray that, if their wickedness has led to your salvation, they too might return to their roots. Then you will please God who has shown you mercy, for he called you so that by making them jealous of you he might bring them to grace as well. Commentary on Paul’s Epistles.