אִם־אַחֶ֖רֶת יִֽקַּֽח־ל֑וֹ שְׁאֵרָ֛הּ כְּסוּתָ֥הּ וְעֹנָתָ֖הּ לֹ֥א יִגְרָֽע׃
אױב ער װעט זיך נעמען אַן אַנדערע, זאָל ער איר שפּײַז, איר קלײדונג, און איר װײַברעכט, ניט מינערן.
Chizkuni
ועונתה, some commentators believe that the root of this word here is עון as in Isaiah 13,22: וענה איים באלמנותיו “ and the wild beasts of the islands shall cry in their desolate palaces.” The letter מ in the word מעון having been replaced similar to the way it has been in the words: מלון, מזון and מדון our verse then would prescribe that if, after marrying the young girl he married additional wives, she continues to be entitled to receive from her husband food, clothing and housing.
Sforno
לא יגרע, one does not have the right to marry more than one woman unless able to provide for them not at the expense of reducing the first wife’s allowance. (Yevamot 65)
Tur HaArokh
צוטריטלעך נאָר פֿאַר פּרעמיום־מיטגלידערSiftei Chakhamim
צוטריטלעך נאָר פֿאַר פּרעמיום־מיטגלידערRav Hirsch
צוטריטלעך נאָר פֿאַר פּרעמיום־מיטגלידערRashi
שארה כסותה וענתה לא יגרע HER FOOD, HER RAIMENT AND THE MARITAL DUTY SHALL HE NOT WITHHOLD — from the maidservant whom he has already designated as his wife.