The father’s (ex-)wife is a mahram to his sons even if she did not bear him any children

Dear Brothers & Sisters,
As-Salaamu-Alaikum wa Rahmatullahi wa Barakatuh. (May Allah's Peace, Mercy and Blessings be upon all of you)
One of our brothers/sisters has asked this question:
My father married his cousin (the daughter of his paternal uncle), but she did not bear him any children, so he divorced her. After that he married another woman, and she is my mother. Is it permissible for me to greet my father’s first wife with salaam or not?
(There may be some grammatical and spelling errors in the above statement. The forum does not change anything from questions, comments and statements received from our readers for circulation in confidentiality.)
Check below answers in case you are looking for other related questions:
Is the husband of her husband's daughter a mahram for her?
It is not permissible to be married to a woman and her paternal or maternal aunt at the same time

Answer:

Praise be to Allah.

Your father’s wife is a mahram to you, whether she bore children or not. 

If he only did the marriage contract with her, and did not consummate the marriage with her, then she is still a mahram to you, because Allah, may He be exalted, said (interpretation of the meaning): “And marry not women whom your fathers married” [an-Nisa’ 4:22]. The wives of fathers and grandfathers become mahrams (to sons and grandsons) as soon as the marriage contract is done. Even if your grandfather or father did not consummate the marriage with her, she is still a mahram to you. If he did consummate the marriage with her and lived with her, then it is more definite that she is a mahram to you, even if she did not bear children. 

To sum up: the wives of fathers and grandfathers are mahrams (to sons and grandsons) regardless of whether they bore children to your father and grandfathers or not. And Allah knows best.

End quote 

Shaykh ‘Abd al-‘Azeez ibn Baaz (may Allah have mercy on him).

Whatever written of Truth and benefit is only due to Allah's Assistance and Guidance, and whatever of error is of me. Allah Alone Knows Best and He is the Only Source of Strength.
Your brother and well wisher in Islam

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Is the husband of her husband's daughter a mahram for her?
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