It is narrated from several Companions (may Allah be pleased with them) that the Noble Prophet (peace and blessings be upon him) said: When a slave woman is granted her freedom, she is given the choice, provided that her husband has not had intercourse with her; if she wishes, she may separate from her husband. But if he has had intercourse with her, then she no longer has this choice and cannot separate from him.
Hadith Referenceمسند احمد / مسند الأنصار رضي الله عنهم / 23208
Hadith Gradingحکم دارالسلام:حديث حسن، وهذا إسناد ضعيف لضعف ابن لهيعة، وقد اختلف عليه فيه