Isma'il bin Umayyah narrates from his father, from his grandfather, that we had a slave who was called Dhakwan or Tahman, and he had a slave of his own, half of whom he set free. This was mentioned to the Prophet (peace and blessings be upon him), and he (peace and blessings be upon him) said: "He will be free with your freedom and remain a slave with your slavery."
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 5496