Zaynab the Daughter of Umm Salamah (RAH) narrated that, "Umm Salamah (RA) said to Aaisha (RA), Verily, the young man who I do not approve to come in (to my apartment) comes in to your apartment? Aaisha (RA) said, Do you not find in the Messenger of Allaah a good example? She said, the wife of Abu Hudhayfah (came to the Messenger and) said, O Messenger of Allaah, Saalim comes in to my apartment and he is a (bearded), matured young man and Abu Hudhayfah (her husband) was not any pleased with it and the Messenger said, Breastfeed him so that he can come into your apartment. She said, How will I breast feed him when he is a grown-up male?The Messenger (sallallahu alayhi wa sallam) smiled and said, I knew he is a grown up male. " (Muslim and Ahmad).
Based on this hadeeth, Aaisha, Urwah bn Zubayr, al-Qaasirn bn Muhammad bn Abee bakr, Ataa bn Abee Rabaah, al-Layth bn Sad, Abu Muhammad bn Hazm al-Andaloosee and Ibn al-Arabee al-Maalikee amongst others rule that giving breast milk to a grown up can also cause prohibition. They state that "to claim (that breastfeeding a grown up to cause prohibition) is only restricted to Saalim requires a proof since they (other wives of the Messenger) acknowledge the fact of the proof presented by Aaisha (RA). Thus, there is no proof in their statement (that it was only restricted to Saalim) since that contradicts what is reported from the Messenger. Were this practice (of prohibition by breastfeeding a grown up) restricted only to Saalim, the Messenger would have made it clear ... Awn al-Mabood (6/47).
So, they conclude that The two sets of ahaadeeth (those showing prohibition by breastfeeding a grown up and prohibition only before weaning) are harmonized by that breastfeeding is basically considered (to prohibit) for children (before weaning) except when a need calls for it like a grown-up male who cannot do without going to a womans apartment such that it becomes a dire difficulty for her to veil herself up away from him each time he has to go into her apartment." Nayl al-Awtaar (7/1 18-123) and Awn al-Mabood (6/47).
This is also the position of Shaykhul-Islam Ibn Taimiyyah (RAH) as quoted in Minnatul-Munim fee Sharh Sahih Muslim (2/415) For those prohibited by fosterage, Allaah says, " (Prohibited for you in Marriage are) Your foster mother who gave you suck, your foster milk suckling sisters ... " (Q4 [Nisaa]:23)
Therefore, the following are those the Muslimah cannot marry due to fosterage -
I.Her foster son (and grandson and great grandson and so on)
2.Her son's foster son (and grandson and so on)
3.Her sister's foster son
4. Her brother's foster son
5.Her grandmother's foster son
6.Her foster brothers. Her foster brothers are of three categories : a.The Foster brother breastfed by the same foster mother and from the same husbands milk b.The foster brother breastfed by the same foster mother and from two different husbands milk c.The foster brother breastfed by a wife of his foster mother (i.e. a co wife of his foster mother)
It should be noted that the foster relationships are restricted to the breastfed person and his offspring. Such relationship does not extend to his blood relatives such as blood brothers and sisters. So it is permissible for example, for the blood brother of someone who was breastfed by a woman to marry such a woman just as it is also permissible for the blood brother of the one who was breastfed to marry the foster sister of his blood brother.
This article was culled from the publications of Deen Communication Limited