Abu al-Hasan, a freed slave of Banu Nawfal, asked Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) for a ruling about a slave who had a slave woman as his wife: he gave his wife two divorces, so she became separated from him; then both of them were freed. Is it proper for the man to propose marriage to her? Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) said: Yes, because the Messenger of Allah (peace and blessings be upon him) "gave this very ruling."
(b) Ibn al-Mubarak (may Allah have mercy on him) said to Ma'mar (may Allah have mercy on him): Who is this Abu al-Hasan? He has burdened himself with a huge rock. By this he meant to reject the hadith he narrated.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الرجعة / 15180