The Prophet ﷺ said, "Whoever frees his share in a jointly owned slave, the slave is fully freed. If the one who freed his share has enough wealth to cover the value of the rest, he must complete the emancipation of the entire slave."
حدثنا يحيى عن عبيد الله أخبرني نافع
عن النبي ﷺ من أعتق شركا له في مملوك فقد عتق كله فإن كان للذي أعتق نصيبه من المال ما يبلغ ثمنه فعليه عتقه كله