John Chrysostom, on Rom 11:20

“Well: because of unbelief they were broken off. But thou standest by faith: be not highminded, but fear.”

“"Well," he praises what they said, then he alarms them again by saying, "Because of unbelief they were broken off, and thou art grafted in by faith." So here another encomium, and for the other party an accusation. But he again lays their pride low by proceeding to say, "be not high-minded, but fear." For the thing is not matter of nature, but of belief and unbelief. And he seems to be again bridling the Gentile, but he is teaching the Jew that it is not right to cling to a natural kinsmanship. Hence he goes on with, "Be not high-minded," and he does not say, but be humble, but, fear. For haughtiness genders a contempt and listlessness. Then as he is going into all the sorrows of their calamity, in order to make the statement less offensive, he states it in the way of a rebuke given to the other as follows:”

Imported from an open dataset — not yet checked against the printed edition.