Narrated Abdullah ibn Abbas: 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).
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا مُسَدَّدٌ، حَدَّثَنَا يَحْيَى، عَنْ شُعْبَةَ، حَدَّثَنِي الْحَكَمُ، عَنْ عَبْدِ الْحَمِيدِ بْنِ عَبْدِ الرَّحْمَنِ، عَنْ مِقْسَمٍ، عَنِ ابْنِ عَبَّاسٍ، عَنِ النَّبِيِّ صلى الله عليه وسلم فِي الَّذِي يَأْتِي امْرَأَتَهُ وَهِيَ حَائِضٌ قَالَ " يَتَصَدَّقُ بِدِينَارٍ أَوْ نِصْفِ دِينَارٍ " . قَالَ أَبُو دَاوُدَ هَكَذَا الرِّوَايَةُ الصَّحِيحَةُ قَالَ " دِينَارٌ أَوْ نِصْفُ دِينَارٍ " . وَرُبَّمَا لَمْ يَرْفَعْهُ شُعْبَةُ .
sunnah.com