Sunan an-Nasa'i, Hadith 3360 ⓘ
It was narrated from An-Nu'man bin Bashir that the Prophet 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)."
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 " .
also referenced under: Book 26, Hadith 165 (In-Book) & Volume 4, Book 26, Hadith 3362 (DarusSalam)