Hazrat Ubaidullah bin Ubaid bin Umair narrates that Abdur Rahman bin Auf sold a slave woman with whom he used to have intercourse, and he was not certain that her womb was empty. The person who bought her found her to be pregnant. So he brought the case before Hazrat Umar (may Allah be pleased with him). Hazrat Umar asked Abdur Rahman, "Did you use to have intercourse with her?" He replied, "Yes." Hazrat Umar (may Allah be pleased with him) said, "Did you sell her without being certain that her womb was empty?" He replied, "Yes." Hazrat Umar said, "It was not appropriate for you to do so." Then he called for experts in lineage, and after they saw the child, they handed the child over to him.

Hasan used to say that when a slave-girl is bought and when a slave-girl is sold, one should wait for one month for istibra (to ascertain her state of purity).

Hazrat Ibn Sirin says that if a man buys a woman who does not menstruate, her waiting period (istibra) will be three months. Then, after having intercourse with her, if he wishes to sell her, he should again wait for three months of istibra.

Ibrahim says that whoever wants to sell a slave-girl should observe istibra’ (waiting period) for her.

Hazrat Ibn Umar (may Allah be pleased with them both) narrates that if a slave woman has been had intercourse with, and then she is sold, or given as a gift, or set free, then it should be ascertained for one menstrual cycle that she is not pregnant.