Milk sibling

Milk kinship, formed during nursing by a non-biological mother, was a form of fostering allegiance with fellow community members. This particular form of kinship did not exclude particular groups, such that class and other hierarchal systems did not matter in terms of milk kinship participation.

Traditionally speaking, this practice predates the early modern period, though it became a widely used mechanism for developing alliances in many hierarchical societies during that time. Milk kinship used the practice of breast feeding by a wet nurse to feed a child either from the same community, or a neighbouring one. This wet nurse played the strategic role in forging relations between her family and the family of the child she was nursing, as well as their community.

In the early modern period, milk kinship was widely practiced in many Arab countries for both religious and strategic purposes. Like the Christian practice of godparenting, milk kinship established a second family that could take responsibility for a child whose biological parents came to harm. "Milk kinship in Islam thus appears to be a culturally distinctive, but by no means unique, institutional form of adoptive kinship." A child in one of these societies would be breastfed by a woman of a lower class, enabling the child's biological mother to maintain her modesty.

The childhood of the Islamic prophet, Muhammad, illustrates the practice of traditional Arab milk kinship. In his early childhood, he was sent away to foster-parents amongst the Bedouin. By nursing him, Halimah bint Abdullah became his "milk-mother." The rest of her family was drawn into the relationship as well: her husband al-Harith became Muhammad's "milk-father," and Muhammad was raised alongside their biological children as a "milk-brother". This case suggests that it was typical for a child's wet nurse to be responsible for raising him.

Sunni Islam prohibits marriage between milk-brothers and milk-sisters, or milk-children and milk-parents. This stricture was sometimes deployed for strategic purposes such as blocking undesirable marriages. Shi'ite Islam goes further in this restriction by also prohibiting marriage to the consanguineous kin of a milk-parent. In early modern Shi'ite societies, though, the wet nurse was always from a subordinate group, so that marriage to her kin would not have been likely.

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Wikipedia