Musnad Ahmad Hadith 20009

It is narrated from Imran bin Husain (may Allah be pleased with him) that a man, at the time of his death, freed all six of his slaves, and he had no wealth other than them. His heirs came and informed the Prophet (ﷺ). The Prophet (ﷺ) said, "If we had known about this earlier, we would not have performed his funeral prayer." The Prophet (ﷺ) called those slaves, divided them into three groups, and drew lots among them. Then, the two whose names were drawn were set free, and the remaining four were kept as slaves.