This hadith has been narrated on the authority of Abu Huraira and Zaid b. Khalid al-Jubani, but in this no merition is made of the words of Ibn Shihab that dafir means rope.
Sahih Muslim Book 29, Hadith 51
← Previous Hadith If she commits adultery, then flog her and if she commits adultery again, then flog her and then sell her even for a rope. Ibn Shihab said: I do not know whether he said this (his statement pertaining to the sale of slave-woman) at the third or the fourth time. Ibn Shihab said that the word dafir (used in the text) means rope.

Sahih Muslim Book 29, Hadith 50 Next Hadith → This hadith has been transmitted on the authority of Abu Huraira and Zaid b. Khalid al-Juhani in the same way as transmitted by Malik with this (difference) tnat there is a doubt whether her sale (that of the slave-girl committing adultery) was mentioned after the third or the fourth time.

Sahih Muslim Book 29, Hadith 52