The ruling on marrying a paternal cousin’s daughter in the presence of breastfeeding

Question:
There is a woman who breastfed her son’s son while he was still in his first week, more than fifteen times. However, this milk is about seven years old. After the boy grew up, he wanted to marry his paternal cousin’s daughter, so his grandmother told him what had happened. She had not mentioned it before this incident. Is it permissible for him to marry that girl? May Allah reward you with good.

Answer:
If what was mentioned in the question is true, and that she breastfed this child extensively, then he becomes her son through breastfeeding, even if a long time has passed since this milk was produced—meaning she had been pregnant and given birth a long time ago, and this milk came to her without pregnancy and without intercourse, and she breastfed the child with it—then, according to the correct view, it is forbidden and establishes the prohibition of marriage. Her son’s son becomes her son, and all of their children become prohibited for this child. It is not permissible for him to marry his paternal cousin’s daughter, nor the daughters of his paternal aunts, because he becomes prohibited for them through breastfeeding. The Messenger of Allah (peace and blessings be upon him) said: , and Allah knows best. May Allah reward you with good, and may He do you good.