Is it permissible for a son to marry his sister's daughter if the father's wife breastfed the sister's daughter twice to satiety during the first two years of life, while the son was not breastfed by the father's wife?
Source: FtawySummary from Ftawy's records · added here Sep 2, 2026
If your sister's daughter breastfeeds from your father's wife five full feedings before the age of two, then your father's wife becomes her foster mother, and your father becomes her foster father. You and her mother become her foster siblings, and your son becomes her foster nephew. If the breastfeeding does not fulfill the conditions for prohibition (five full feedings before two years of age), then marriage is permissible. However, it is preferable to avoid it as a precaution due to a jurisprudential difference of opinion.
Summary from Ftawy's records · added here
Reviewed by El Fatwa's sharia committee.
Read the full answer on Ftawyhttps://ftawy.com/en/questions/68234
Where this answer came from
- Source platform
- Ftawy
- Original fatwa ID
- 68234
- Added here
- . This is when the answer was added to El Fatwa, not the fatwa's date.
- Text
- Summary from Ftawy's records, reviewed by El Fatwa's sharia committee.
- Read the full ruling
- Read the full answer on Ftawy