قَالَ أَبِي وَأَخْبَرَنَا يَعْنِي يَزِيدَ قَالَ أَخْبَرَنَا يَحْيَى عَنْ نَافِعٍ عَنِ ابْنِ عُمَرَ كَانَ يَقُولُ قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ مَنْ أَعْتَقَ نَصِيبًا لَهُ فِي إِنْسَانٍ أَوْ مَمْلُوكٍ كُلِّفَ عِتْقَ بَقِيَّتِهِ فَإِنْ لَمْ يَكُنْ لَهُ مَالٌ يُعْتِقُهُ بِهِ فَقَدْ جَازَ مَا عَتَقَ
مسند امام احمد بن حنبل · Hadith 5474
It was narrated from ibn 'Umar that the Messenger of Allah (PBUH) used to say: "Whoever frees his share in a person or a slave is obliged to free the rest of him. If he does not have wealth with which to free him, then whatever he has freed of him is valid."
Sanad
قَالَ أَبِي وَأَخْبَرَنَا يَعْنِي يَزِيدَ قَالَ أَخْبَرَنَا يَحْيَى عَنْ نَافِعٍ عَنِ ابْنِ عُمَرَ