Tirmidhi

Explanation:

➊:
These are the seven relationships: (1) mothers, (2) daughters, (3) sisters, (4) paternal aunts (phuphi), (5) maternal aunts (khala), (6) nieces (brother’s daughters), (7) nieces (sister’s daughters).

Grandmothers (both paternal and maternal) are included under “mothers,” and granddaughters (both son’s and daughter’s daughters) are included under “daughters.”

There are three types of sisters: full sisters (from both parents), half-sisters (from the father’s side), and half-sisters (from the mother’s side).

Similarly, nieces (brother’s and sister’s daughters) are included even if they are from a lower degree, and paternal aunts (phuphi) are included whether they are full, half (from the father’s side), or half (from the mother’s side).

Likewise, the paternal aunts of the father, grandfather, mother, and grandmother are all prohibited (for marriage), and the same applies to maternal aunts (khala) accordingly.

Hazrat Hamzah radi Allahu anhu’s daughter was, in terms of lineage, the paternal cousin of the Messenger of Allah sallallahu alayhi wa sallam, and thus marriage with her was permissible for him. For this reason, Hazrat Ali radi Allahu anhu proposed marriage to her. However, she was also his foster niece, because both the Messenger of Allah sallallahu alayhi wa sallam and Hazrat Hamzah radi Allahu anhu had been breastfed by Thuwaibah. In this respect, they were foster brothers. Therefore, marriage to his (foster) brother’s daughter was not permissible, because a foster niece is like a biological niece.