The Ruling on the Father’s Children from Breastfeeding from His Second Wife

Question: I was breastfed by a woman, and then her husband married another woman, and his wife gave birth to sons. Are they my brothers?

Answer: If the breastfeeding was five sucklings or more, and the milk was attributed to the husband because she bore a child from him, then they are your brothers from your father and mother through breastfeeding. As for his children from the second wife, they are your brothers from your father through breastfeeding.
A suckling is defined as the child holding the breast and sucking the milk until it reaches his stomach, then releasing the breast for any reason, then returning to suckle the breast until the milk reaches his stomach, then stopping the breastfeeding, then returning, and so on until five or more are completed—whether that occurs in one sitting or multiple sittings, and whether it occurs in one day or multiple days—on the condition that this happens while the child is within the two-year period. This is based on the saying of the Prophet (peace and blessings be upon him): , and his saying to Sahlah bint Sahl: , and what is established in Sahih Muslim and the Jami' of al-Tirmidhi, from 'Aishah (may Allah be pleased with her), who said: “It was among what was revealed in the Qur'an that ten sucklings establish prohibition, then they were abrogated by five known sucklings. The Prophet (peace and blessings be upon him) passed away while the matter remained as such.” This is the wording of al-Tirmidhi’s narration. May Allah guide everyone to what pleases Him.