صَحِيحُ مُسْلِمٍ
Sahih Muslim 1503 d
The Book of Oaths
One who frees his share in a slave
وَحَدَّثَنَا عُبَيْدُ اللَّهِ بْنُ مُعَاذٍ، حَدَّثَنَا أَبِي، حَدَّثَنَا شُعْبَةُ، بِهَذَا الإِسْنَادِ قَالَ مَنْ أَعْتَقَ شَقِيصًا مِنْ مَمْلُوكٍ فَهُوَ حُرٌّ مِنْ مَالِهِ .
This hadith has been narrated on the authority of Shu'ba with the same chain of transmitters (and the words are): " He who emancipates a portion in a slave, he should (secure full) freedom for him from his property."
Sahih Muslim, 1503 dSahihصحيح