Hadith on Marriage: Do not marry a second wife if first wife is harmed by it

Al-Miswar ibn Makhramah reported: I heard the Messenger of Allah, peace and blessings be upon him, say upon the pulpit, “Verily, the sons of Hisham ibn Al-Mughirah have sought my permission to marry their daughters to Ali ibn Abi Talib. I do not give permission, again I do not give permission, and again I do not give permission unless Ali ibn Abi Talib intends to divorce my daughter and marry their daughters. Verily, she is only a part of me. I am upset by what upsets her, and I am harmed by what harms her.”

Source: Ṣaḥīḥ al-Bukhārī 4932, Ṣaḥīḥ Muslim 2449

Grade: Muttafaqun Alayhi (authenticity agreed upon) according to Al-Bukhari and Muslim

An-Nawawi said, “The Prophet prohibited that because of his perfect compassion for Ali and for Fatimah, and secondly because he feared she would be tested with jealousy.”

Source: Sharḥ al-Nawawī ‘alá Ṣaḥīḥ Muslim 2449