Marriage to the mother of a child who was breastfed by the same mother as the man’s brother

The questioner:
He says: Honorable Shaykh, may Allah grant you success. He says: One of my neighbors’ children was breastfed by my mother, so is it permissible for me to marry his mother?

The Shaykh:
One of the neighbors.

The questioner:
Was breastfed.

The Shaykh:
I mean, is your neighbor’s elder, an adult man, breastfed by your mother? Is that acceptable? Or did you mean a boy, i.e., an infant, who was breastfed by your mother? Is it permissible for you to marry his mother? What is the obstacle? There is no obstacle to marrying the mother of the one who was breastfed by your mother. Yes.

The questioner:
Yes.

The Shaykh:
I am a stranger to your mother, and there is no breastfeeding relationship between you and her. Yes.

The questioner:
He says: Honorable Shaykh.

The Shaykh:
The rule is that breastfeeding kinship extends only to the breastfed child and his descendants, such as his sons and daughters, and does not extend to his brothers or his ancestors, such as his father and mother.