Bulugh al-Maram, Book 1, Hadith 175 (In-Book)

Narrated Ibn `Abbas (RAA): Allah's Messenger (Peace be upon him) said regarding a husband who has sexual intercourse with his wife during her menstruation period, "He must pay a Dinar or half a Dinar in way of charity.” [Reported by the five Imams. Al-Hakim and Ibn Al-Qattan graded it Sahih (sound).]

وَعَنِ اِبْنِ عَبَّاسٍ رَضِيَ اَللَّهُ عَنْهُمَا, عَنِ اَلنَّبِيِّ ‏- صلى الله عليه وسلم ‏-‏-فِي اَلَّذِي يَأْتِي اِمْرَأَتَهُ وَهِيَ حَائِضٌ‏- قَالَ: { يَتَصَدَّقُ بِدِينَارٍ, أَوْ نِصْفِ دِينَارٍ } رَوَاهُ اَلْخَمْسَةُ, وَصَحَّحَهُ اَلْحَاكِمُ وَابْنُ اَلْقَطَّانِ, وَرَجَّحَ غَيْرَهُمَا وَقْفَه ُ (174)‏.‏ ‏1 ‏- صحيح مرفوعا.‏ باللفظ الذي ذكره الحافظ فقط.‏ رواه أبو داود (264)‏، والنسائي (153)‏، والترمذي (136)‏، وابن ماجه (640)‏، وأحمد (172)‏، والحاكم (172)‏.‏

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also referenced under: Book 1, Hadith 157 (English)