Sunan an-Nasai 19444
In-book no 4708أَخْبَرَنَا نُوحُ بْنُ حَبِيبٍ، قَالَ أَنْبَأَنَا عَبْدُ الرَّزَّاقِ، قَالَ أَنْبَأَنَا مَعْمَرٌ، عَنِ الزُّهْرِيِّ، عَنْ سَالِمٍ، عَنْ أَبِيهِ، أَنَّ النَّبِيَّ صلى الله عليه وسلم قَالَ " مَنْ أَعْتَقَ شِرْكًا لَهُ فِي عَبْدٍ أُتِمَّ مَا بَقِيَ فِي مَالِهِ إِنْ كَانَ لَهُ مَالٌ يَبْلُغُ ثَمَنَ الْعَبْدِ " .
It was narrated from Salim, from his father, that the Messenger of Allah said: "Whoever sets free his share of a slave should set him free completely from his own wealth, if he has enough wealth to cover the price of the slave."