Muwatta Imam Malik Book of Divorce, Hadith 23

Yahya related to me from Malik from Hisham ibn Urwa that he heard a man ask Urwa ibn az-Zubayr about a man who said to his wife, "Any woman I marry along with you as long as you live will be like my mother's back to me." Urwa ibn az-Zubayr said, "The freeing of slaves is enough to release him from that."

وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ هِشَامِ بْنِ عُرْوَةَ، أَنَّهُ سَمِعَ رَجُلاً، يَسْأَلُ عُرْوَةَ بْنَ الزُّبَيْرِ عَنْ رَجُلٍ، قَالَ لاِمْرَأَتِهِ كُلُّ امْرَأَةٍ أَنْكِحُهَا عَلَيْكِ مَا عِشْتِ فَهِيَ عَلَىَّ كَظَهْرِ أُمِّي . فَقَالَ عُرْوَةُ بْنُ الزُّبَيْرِ يُجْزِئُهُ عَنْ ذَلِكَ عِتْقُ رَقَبَةٍ .