Is a marriage contract valid if a free man marries a slave woman while already married to a free woman?
Chapter on What is Prohibited to Marry and Combining Between Them and Other Matters
Al-Mughni
Book of Marriage
Primary text
The marriage contract of a free man marrying a slave woman while married to a free woman is valid. This opinion is held by Sa'id ibn al-Musayyib, 'Ata', Al-Shafi'i, and the Ashab al-Ra'y (the companions of the view). A meaning supporting this was narrated from 'Ali (may Allah be pleased with him). The evidence cited is the narration attributed to 'Ali that if a free woman is married onto a slave woman, the free woman is given two nights and the slave woman one night. This implies the marriage remains valid, because if it were nullified by the marriage to the free woman, it would be nullified by the mere capability of obtaining the free woman, analogous to the ruling regarding water and soil.
Supporting text
There are two narrations regarding the invalidity of the marriage to the slave woman. This view is held by Ibn 'Abbas, Masruq, Ishaq, and Al-Muzani. Al-Nakhai stipulated that if the existing children are from the slave woman, the man does not separate from her; otherwise, he must separate. This stipulation is rejected because whatever invalidates the marriage for someone without existing children invalidates it for someone with them, similar to all other nullifying factors. Furthermore, any child born to the slave woman would be owned by her master, and the father would be responsible for the child's maintenance.