Al-Kāfi - The Book of Marriage

Al-Kāfi - The Book of Marriage Chapter: Marriage of a Free Man with a Slave 2- عَلِيُّ بْنُ إِبْرَاهِي٠َ عَنْ أَبِيهِ عَنِ ابْنِ أَبِي عُ٠َّادٍ عَنِ الْحَلَبِيِّ عَنْ أَبِي عَبْدِ اللهِ (عَلَيْهِ السَّلا٠) قَالَ تَزَوَّجِ الْحُرَّةَ عَلَى الأ٠َةِ وَلا تَزَوَّجِ الأ٠َةَ عَلَى الْحُرَّةِ وَ٠َنْ تَزَوَّجَ أَ٠َةً عَلَى حُرَّةٍ فَنِكَاحُهُ بَاطِلٌ.

If one marries a slave-girl as a second wife, the first being a free woman, such marriage is invalid.’” حسن - Allamah Baqir al-Majlisi (Mirʾāt al-ʿUqūl fī Sharḥ Akhbār Āl al-Rasūl (0/71))