Wa`alaykum as-salam wa rahmatullahi wa barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
A non-Muslim wife is not required to abide by the Islamic Shari`ah-related matters such as “intention” or following the exact method of performing ghusl. Therefore, as long as she has taken a full bath after menses, there is nothing wrong in having sexual intercourse with her.
In her response to your question, the prominent Muslim scholar and da`iyah, Zeinab Mostafa, states:
Practically, she has purified herself and she is no longer menstruating.
As for the niyyah and proper Islamic way of making ghusl, these are Shari`ah-related matters that she is not required to do since she is not a Muslim.
Therefore, there is nothing wrong in having sexual intercourse with her as long as she has taken a complete bath.
Almighty Allah knows best.
Editor’s note: This fatwa is from Ask the Scholar’s archive and was originally published at an earlier date.