The Book of Purification and its Sunnah
1/129. Chapter:
One who has intercourse with his wife when she is menstruating
Sunan Ibn Majah
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 650In-book reference : Book 1, Hadith 384English translation : Vol. 1, Book 1, Hadith 650