ENOfficial
It was narrated from An-Nu'man bin Bashir that the Prophet (ﷺ) said, concerning a man who had intercourse with his wife's slave woman: "If she let him do that, I will flog him with one hundred stripes , and if she did not let him, I will stone him (to death)."
Source: sunnah.com
Other translations
Arabic
أَخْبَرَنَا مُحَمَّدُ بْنُ بَشَّارِ، قَالَ حَدَّثَنَا مُحَمَّدٌ، قَالَ حَدَّثَنَا شُعْبَةُ، عَنْ أَبِي بِشْرٍ، عَنْ خَالِدِ بْنِ عُرْفُطَةَ، عَنْ حَبِيبِ بْنِ سَالِمٍ، عَنِ النُّعْمَانِ بْنِ بَشِيرٍ، عَنِ النَّبِيِّ صلى الله عليه وسلم فِي الرَّجُلِ يَأْتِي جَارِيَةَ امْرَأَتِهِ قَالَ " إِنْ كَانَتْ أَحَلَّتْهَا لَهُ جَلَدْتُهُ مِائَةً وَإِنْ لَمْ تَكُنْ أَحَلَّتْهَا لَهُ رَجَمْتُهُ " .
sunnah.com