Surah Al-Baqarah
وَيَسْـَٔلُونَكَ عَنِ ٱلْمَحِيضِ ۖ قُلْ هُوَ أَذًى فَٱعْتَزِلُوا۟ ٱلنِّسَآءَ فِى ٱلْمَحِيضِ ۖ وَلَا تَقْرَبُوهُنَّ حَتَّىٰ يَطْهُرْنَ ۖ فَإِذَا تَطَهَّرْنَ فَأْتُوهُنَّ مِنْ حَيْثُ أَمَرَكُمُ ٱللَّهُ ۚ إِنَّ ٱللَّهَ يُحِبُّ ٱلتَّوَّٰبِينَ وَيُحِبُّ ٱلْمُتَطَهِّرِينَ
Wa yas'alūnaka ‘anil-maḥīḍ(i), qul huwa ażā(n), fa‘tazilun-nisā'a fil-maḥīḍ(i), wa lā taqrabūhunna ḥattā yaṭhurn(a), fa'iżā taṭahharna fa'tūhunna min ḥaiṡu amarakumullāh(u), innallāha yuḥibbut-tawwābīna wa yuḥibbul-mutaṭahhirīn(a).
And they ask you about menstruation. Say, "It is harm, so keep away from wives during menstruation. And do not approach them until they are pure. And when they have purified themselves, then come to them from where Allah has ordained for you. Indeed, Allah loves those who are constantly repentant and loves those who purify themselves."
📝 Footnotes
65) Menstruation (hayd) is blood discharged along with tissue that was prepared for fertilization in a woman's uterus. Its discharge is periodic, corresponding to the period of egg cell release into the uterus. This condition is considered impure and renders a woman ritually unclean (shar'i), which includes being unclean for sexual relations with her husband.