The uncle’s wife is not a mahram

Question:
This is a questioner for the program (Al-Awfi) from the village of Qusaybah, who says: O Shaykh! Is the uncle’s wife a mahram or not? Because I heard that the grandfather’s wife is not a mahram, but the uncle’s wife is a mahram whom it is not permissible to marry after her husband’s death or his divorce from her?

Answer:
The uncle’s wife, the grandfather’s wife, and the brother’s wife are not mahrams. If her husband dies or divorces her and she exits the waiting period, it is permissible for her brother’s son to marry her; there is no harm. The brother’s wife: the brother is closer, yet his wife is not a mahram. A mahram is the father’s wife, the grandfather’s wife, and the son’s wife. As for the brother’s wife, the uncle’s wife, and the grandfather’s wife, they are not mahrams; rather, she is a stranger. His uncle’s wife is a stranger, his grandfather’s wife is a stranger, and his brother’s wife is a stranger. He must not be alone with her, and she must not uncover herself before him. Yes.

The presenter: May Allah preserve you, O honorable Shaykh.