The Prophet ﷺ said, "If a slave-woman commits adultery and her adultery is proven, let him flog her without rebuking her. If she commits it again, let him flog her without rebuking her. If she commits it a third time, let him sell her, even for a rope of hair."
قال النبي ﷺ: إذا زنت الأمة فتبين زناها فليجلدها ولا يثرب، ثم إن زنت فليجلدها ولا يثرب، ثم إن زنت الثالثة فليبعها ولو بحبل من شعر.
Bukhari narrated it in the Book of Sales (2152), and Muslim in the Book of Legal Punishments (1703), both through the route of Layth, who said, Saeed bin Abu Saeed Maqburi narrated to me, from his father, from Abu Hurairah.As for his saying, "then let him sell it," this means along with disclosing its defect, since concealing defects is not permissible according to the general body of evidence.