I had sexual intercourse with my wife after she had made Ghusl for menstruation. On the next morning, however, she discovered that she had not removed the nail polish before Ghusl. What is the Sharee‘ah ruling on this case?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.

The sound opinion adopted by the majority of the scholars of Fiqh is that it is impermissible to have sexual intercourse with one's wife unless she makes Ghusl after menstruation or post-partum bleeding. Meanwhile, nail polish prevents water to reach the body and this renders Ghusl invalid. Consequently, your wife is required to make up Ghusl after removing the nail polish. She is also required to make up the prayers she performed with an invalid Ghusl.

Since you were certain that Ghusl was valid, you are blameless for the sexual intercourse and this is forgiven Inshaa’ Allaah. Allaah The Almighty Says (what means): {Our Lord, do not impose blame upon us if we have forgotten or erred.}[Quran 2: 286]

Likewise, the Prophet, sallallaahu ‘alayhi wa sallam, said: "Allaah Has Forgiven my Ummah for (things done out of) mistake, forgetfulness or coercion." [Ibn Maajah and Ibn Hibbaan. Saheeh Hadeeth]