הִמֹּ֣לוּ לַיהֹוָ֗ה וְהָסִ֙רוּ֙ עָרְל֣וֹת לְבַבְכֶ֔ם אִ֥ישׁ יְהוּדָ֖ה וְיֹשְׁבֵ֣י יְרוּשָׁלִָ֑ם פֶּן־תֵּצֵ֨א כָאֵ֜שׁ חֲמָתִ֗י וּבָעֲרָה֙ וְאֵ֣ין מְכַבֶּ֔ה מִפְּנֵ֖י רֹ֥עַ מַעַלְלֵיכֶֽם׃
Tâchez de vous circoncire en l’honneur de l’Éternel et d’enlever les excroissances de votre cœur; sans cela ma colère éclatera comme le feu, et brûlera sans qu’on puisse l’éteindre, à cause de la perversité de vos actes."
Ibn Ezra
his foreskin It is understood that the foreskin of his genital is meant, as there is no such thing as a foreskin of a heart [Deuteronomy 10:16], or a lip [Exodus 6:12], or an ear [Jeremiah 6:10] — these are all metaphors.
Rashbam
הרמו, a similar construction in the imperative mode to המולו in Jeremiah 4,4. However, on account of the letter ר in our word the vowel chirik has been changed to the vowel tzeyre. We encounter similar changes in the vowel pattern in such words as ברך, beyrech, and birech on account of the dagesh. The reason why the Torah speaks here of הרמו instead of הבדלו in 16,21 which was a far weaker command is that by now G’d’s anger was at full strength as Korach’s punishment had apparently not had the desired effect.