The Messenger of Allah ﷺ was asked about a slave-woman who commits fornication, and she is not married: If she commits fornication, flog her: if she commits fornication again flog her; if only for a rope of hair (dafir). Ibn Shihab: I do not know whether he (the Prophet) said it is a third or a fourth time. (Using translation from Abū Dāʾūd 4469)   

أخْبَرَهُ أَنَّ رَسُولَ اللهِ ﷺ قَالَ لِلْوَلِيدَةِ إِنْ زَنَتْ فَاجْلِدُوهَا ثُمَّ إِنْ زَنَتْ فَاجْلِدُوهَا ثُمَّ إِنْ زَنَتْ فَاجْلِدُوهَا ثُمَّ إِنْ زَنَتْ فَبِيعُوهَا وَلَوْ بِضَفِيرٍ وَالضَّفِيرُ الْحَبْلُ فِي الثَّالِثَةِ أَوْ فِي الرَّابِعَةِ  

[Machine] He informed him that the Prophet ﷺ said regarding the slave girl: If she commits adultery, then flog her. If she commits adultery again, then flog her. If she commits adultery again, then flog her. If she commits adultery again, then sell her, even if it is for a rope.  

أَخْبَرَهُ أَنَّ النَّبِيَّ ﷺ قَالَلِلْوَلِيدَةِ إِنْ زَنَتْ فَاجْلِدُوهَا ثُمَّ إِنْ زَنَتْ فَاجْلِدُوهَا ثُمَّ إِنْ زَنَتْ فَاجْلِدُوهَا ثُمَّ إِنْ زَنَتْ فَبِيعُوهَا وَلَوْ بِضَفِيرٍ وَالضَّفِيرُ الْحَبْلُ