What is the method for a master to negate the lineage of his female slave's offspring if affiliation is established?
General Chapter
Al-Mughni
Book of Mutual Imprecation (Li'an)
Primary text
If the master wishes to negate the lineage of his slave's offspring, which is otherwise attributed to him due to intercourse, the method is for him to claim that he sought purification (*Istibra'*) of her by waiting one menstrual cycle after the intercourse. If he claims *Istibra'*, the child's lineage is negated from him. This is supported by the Prophet's instruction to use *Istibra'* and the narration from Ibn 'Umar regarding 'Umar's judgment that any child born from a slave woman whose master admits intimacy must be affiliated to him, thus commanding *Istibra'* henceforth.
Supporting text
If the master claims he practiced *azl* (coitus interruptus) while having intercourse with her, the lineage is not negated thereby, as evidenced by the narration of Jabir regarding the Ansari man who sought permission for *azl* and the child was subsequently born, and the Prophet confirmed that what was destined for her would reach her regardless. If the master claims *Istibra'*, his word is accepted without an oath according to one scholarly opinion, similar to a woman claiming the end of her waiting period (*Iddah*). Another opinion requires him to swear an oath, following the general principle, 'The oath belongs to the defendant.'