en_tn/rom/11/21.md

For if God did not spare the natural branches, neither will he spare you

Here the "natural branches" refers to the Jewish people who rejected Jesus. Alternate translation: "Since God did not spare those unbelieving Jews, who grew up like a tree's natural branches that came from the root, then know that if you do not believe, he will not spare you either" (See: rc://en/ta/man/translate/figs-metaphor)