Boast not against the branches. But if you boast, you bear not the root, but the root you.
All Commentaries on Romans 11:18 Go To Romans 11
Ambrosiaster
AD 400
It displeases God if someone rejoices at the misfortune of others, as Solomon says. In any case, the Jews were not rejected for the sake of the Gentiles. Rather, it was because they were rejected that they gave an opportunity for the gospel to be preached to the Gentiles. If you boast against those onto whose root you have been grafted, you insult the people who have accepted you so that you might be converted from bad to good. You will not continue like that if you destroy the thing on which you stand. Commentary on Paul’s Epistles.