Source: Fatāwā Amunpuri by Shaykh Ghulam Mustafa Zaheer Amunpuri
Question:
What is the ruling if a man marries his son's widow and has children with her?
Answer:
Such offspring are illegitimate. Separation must be enforced between the father and the son's widow, because a father-in-law and daughter-in-law can never be lawful spouses to each other. This falls under the category of permanently prohibited relationships (محرمات أبدیہ) in Islam.
Allah Almighty says:
﴿وَحَلَائِلُ أَبْنَائِكُمْ﴾
(Surah An-Nisā’, 23)
"And the (wives) of your sons (are forbidden to you in marriage).”
Question:
What is the ruling if a man marries his son's widow and has children with her?
Answer:
Such offspring are illegitimate. Separation must be enforced between the father and the son's widow, because a father-in-law and daughter-in-law can never be lawful spouses to each other. This falls under the category of permanently prohibited relationships (محرمات أبدیہ) in Islam.
Allah Almighty says:
﴿وَحَلَائِلُ أَبْنَائِكُمْ﴾
(Surah An-Nisā’, 23)
"And the (wives) of your sons (are forbidden to you in marriage).”
