Hadith 650
Chapter 129: One who has intercourse with his wife when she is menstruating - كتاب الطهارة وسننها
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ الْجَرَّاحِ، حَدَّثَنَا أَبُو الأَحْوَصِ، عَنْ عَبْدِ الْكَرِيمِ، عَنْ مِقْسَمٍ، عَنِ ابْنِ عَبَّاسٍ، قَالَ كَانَ الرَّجُلُ إِذَا وَقَعَ عَلَى امْرَأَتِهِ وَهِيَ حَائِضٌ أَمَرَهُ النَّبِيُّ ـ صلى الله عليه وسلم ـ أَنْ يَتَصَدَّقَ بِنِصْفِ دِينَارٍ .
It was narrated that Ibn 'Abbas said:
"If a man had intercourse with his wife while she was menstruating, the Prophet commanded him to give half a Dinar in charity."
Reference : Sunan Ibn Majah 650
In-book reference : Book 1, Hadith 384