The Prophet ﷺ said about a person who had intercourse with his wife while she was menstruating: He must give one dinar or half a dinar in alms. Abu Dawud said: The correct version says si: One dinar or half a dinar. Shu'bah (a narrator) did not sometimes narrate this tradition as a statement of the Prophet ﷺ.  

عَنِ النَّبِيِّ ﷺ فِي الَّذِي يَأْتِي امْرَأَتَهُ وَهِيَ حَائِضٌ قَالَ يَتَصَدَّقُ بِدِينَارٍ أَوْ نِصْفِ دِينَارٍ  

If one has intercourse in the beginning of the menses,(one should give) one dinar; in case one has intercourse towards the end of the menses, then half a dinar (should be given)  

إِذَا أَصَابَهَا فِي أَوَّلِ الدَّمِ فَدِينَارٌ وَإِذَا أَصَابَهَا فِي انْقِطَاعِ الدَّمِ فَنِصْفُ دِينَارٍ  

Ibn ‘Abbas reported the Prophet (May peace be upon him) as saying; when a man has intercourse with his wife while she is menstruating, he must give half a dinar in alms. Abu Dawud said; ‘Ali b. Budhaimah reported similarly on the authority of Miqsam from the Prophet (May peace be upon him). Al-Awza’I narrated from Yazid b. Abi Malik, from ‘Abd al-Hamid b. ‘Abd al-Rahman from the Prophet (May peace be upon him); He ordered him to give two fifth of a dinar in alms. But this is a chain where two narrators (Miqsam and Ibn ‘Abbas) are missing.  

عَنِ النَّبِيِّ ﷺ قَالَ إِذَا وَقَعَ الرَّجُلُ بِأَهْلِهِ وَهِيَ حَائِضٌ فَلْيَتَصَدَّقْ بِنِصْفِ دِينَارٍ