"If a man had intercourse with his wife while she was menstruating, the Prophet commanded him to give half a Dinar in charity."  

كَانَ الرَّجُلُ إِذَا وَقَعَ عَلَى امْرَأَتِهِ وَهِيَ حَائِضٌ أَمَرَهُ النَّبِيُّ ﷺ أَنْ يَتَصَدَّقَ بِنِصْفِ دِينَارٍ