Sunan an-Nasa'i, Book 1, Hadith 291 (In-Book) ⓘ
It was narrated from Ibn 'Abbas from the Prophet concerning a man who has had intercourse while she was menstruating: "Let him give a Dinar or half a Dinar in charity."
أَخْبَرَنَا عَمْرُو بْنُ عَلِيٍّ، قَالَ حَدَّثَنَا يَحْيَى، عَنْ شُعْبَةَ، عَنِ الْحَكَمِ، عَنْ عَبْدِ الْحَمِيدِ، عَنْ مُقْسَمٍ، عَنِ ابْنِ عَبَّاسٍ، عَنِ النَّبِيِّ صلى الله عليه وسلم فِي الرَّجُلِ يَأْتِي امْرَأَتَهُ وَهِيَ حَائِضٌ يَتَصَدَّقُ بِدِينَارٍ أَوْ بِنِصْفِ دِينَارٍ .
also referenced under: Volume 1, Book 1, Hadith 290 (DarusSalam)