Sunan Ibn Majah, Book 1, Hadith 694 (In-Book) ⓘ
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."
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 .
also referenced under: Hadith 650 (Reference) & Volume 1, Book 1, Hadith 650 (DarusSalam)