It is narrated from Sayyiduna Imran bin Husayn (may Allah be pleased with him) that a man freed his six slaves at the time of his death. He had no wealth other than them. When the Prophet (peace and blessings be upon him) came to know of it, he (peace and blessings be upon him) spoke very severely about it. Then he called them, cast lots between them, freed two and kept four in slavery.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الوصايا / 12592