7. Ali ibn Ibrahim has narrated from his father from ibn abu ‘ Umayr from Hammad from al-Halabiy who has said the following:

“About the case of a man who divorces his wife or she arranges for al-Khula (payment for divorce) or she becomes a stranger to him; if he can marry her sister. He (the Imam) said, ‘When she has freed herself from responsibility and he is not able to go back to her, it then is permissible for him to propose marriage to her sister.’ He (the narrator) has said that he (the Imam) was asked about the case of a man who has two sisters as his slave-girls. He goes to bed with one of them, then he goes to bed with the other one. He (the Imam) said, ‘When he goes to bed with the other one the first one becomes unlawful for him until the other one dies.’ I then asked, ‘What happens if he sells her?’ He (the Imam) said, ‘If he sells her because of a reason without anything in his mind about the other slave-girl, then I do not see it as harmful; but if he sells her so he can go to the first one, then it is not permissible and it is not honorable.’”