(12) باب مَنْ أَعْتَقَ شِرْكًا لَهُ فِي عَبْدٍ
Abu Huraira reported Allah's Apostle (ﷺ) as saying:
He who emancipates his portion in a slave, full emancipation may be secured for him out of his property (if he has money) if he has enough property to meet (the required expenses), but if he has not enough property, the slave should be put to extra labour (in order to earn money for buying his freedom), but he should not be overburdened.
Reference: Sahih Muslim 1503 e
In-book reference: Book 27, Hadith 81
USC-MSA web (English) reference(deprecated numbering scheme): Book 15, Hadith 4110