The Apostle Paul
Romans 11:21BSB·traditional attribution

For if God did not spare the natural branches, He will certainly not spare you either.

John Calvin Reformed @genevareformer

21. For if God has not spared the natural branches, etc. This is a most powerful reason to beat down all self-confidence: for the rejection of the Jews should never come across our minds without striking and shaking us with dread. For what ruined them, but that through supine dependence on the dignity which they had obtained, they despised what God had appointed?

Matthew Henry Presbyterian @wholebiblehenry

The apostle proposes here a plausible objection, which might be urged against the divine conduct in casting off the Jewish nation (Rom 11:1): "Hath God cast away his people? Is the rejection total and final? Are they all abandoned to wrath and ruin, and that eternal?

Commenting on Romans 11:1-32

John Gill Reformed Baptist @doctorgill

For if God spared not the natural branches,.... That is, executed his righteous judgments, inflicted due punishment upon the Jews, unchurched them, and stripped them of those privileges they enjoyed in a church state; who were the natural descendants of Abraham; were naturally, and as born into the world, in a national church state and in that national covenant God made with that people; to...