The Prophet (ﷺ) said, "If a slave-girl (Ama) commits illegal sexual intercourse, scourge her; if she does it
again, scourge her again; if she repeats it, scourge her again." The narrator added that on the third or
the fourth offense, the Prophet (ﷺ) said, "Sell her even for a hair rope."
Sahih al-Bukhari Book 49, Hadith 38