Section: Abu Abdullah (Ahmad ibn Hanbal) disliked breastfeeding with the milk of those involved in immorality (fujur) and idolatrous women (mushrikat). Umar ibn al-Khattab and Umar ibn Abd al-Aziz—may God be pleased with them both—said: "Milk resembles," so do not let a Jewish, Christian, or adulterous woman breastfeed your child. Furthermore, the people of the dhimma (protected non-Muslims) should not be accepted to breastfeed a Muslim child, nor should their dispositions be sought. This is because the milk of an immoral woman might lead to the child resembling the wet nurse in her immorality, and it makes her a mother to his child, which brings shame upon him, causes him harm in nature and reputation, and breastfeeding from an idolatrous woman makes her a mother, granting her the sanctity of a mother despite her polytheism, and he might incline towards her in affection for her religion. Breastfeeding with the milk of a foolish woman is also disliked, so that the child might not resemble her in foolishness, for it is said that breastfeeding changes dispositions. And God Almighty knows best.

Book of Maintenance (Nafaqat)