this nipple, not through a single opening, but through several tiny openings, so that it does not flow down too quickly and cause the child to choke and die. In all of this, Allah’s wisdom becomes clear, and one should not depart from this great wisdom by giving the child foreign milk, as some people do. Doctors are agreed that a mother’s milk is better for the child than any other milk. This accords with Allah’s universal and legislative wisdom. Therefore, a woman should not cease breastfeeding her child for two full years, as Allah Most High says:
“Mothers may breastfeed their children for two complete years—for those who wish to complete the term of breastfeeding.” [al-Baqarah 2:233]
Breastfeeding shares certain rulings with blood kinship, though it differs from it in most respects. Among the matters in which it shares the same ruling is what the author mentions in his statement:
“Through breastfeeding, the same relationships are forbidden as are forbidden through blood kinship.”
“Through breastfeeding, the same relationships are forbidden as are forbidden through blood kinship.” This sentence is the wording of the hadith narrated from the Prophet, peace and blessings be upon him. Thus, it is a legal issue accompanied by its proof. That is, whatever is forbidden by lineage—that is, by blood relationship—is likewise forbidden by breastfeeding.
Let us consider this by enumeration. Read the noble verse:
“Forbidden to you are your mothers, your daughters, your sisters, your paternal aunts, your maternal aunts, the daughters of your brother, and the daughters of your sister.” [al-Nisa’ 4:23]
These are seven. Thus, through breastfeeding, the same relationships are forbidden to a person as are forbidden through blood kinship: his foster mother, foster daughter, foster sister, foster paternal aunt, foster maternal aunt, his sister’s daughter, and his brother’s daughter—exactly as stated in the verse.
Accordingly, do not burden yourself. If someone asks you about an issue involving breastfeeding, consider the relationship between the nursling and the woman who breastfed him: is it motherhood, daughterhood, sisterhood, paternal-aunt relationship, or maternal-aunt relationship? For the hadith is definitive, and the verse is definitive.