Sunan Ibn Majah, Volume 3, Book 19, Hadith 2530 (DarusSalam) ⓘ

It was narrated from Ishaq bin Ibrahim, from his grandfather 'Umair, who was the freed slave of Ibn Mas'ud, that `Abdullah said to him: “O Umair, I have set you free in a good way. I heard the Messenger of Allah say: 'Any man who frees a slave and does not say anything about his (the slave's) wealth, it belongs to him (the slave).' So tell me, how much wealth do you have?”

حَدَّثَنَا مُحَمَّدُ بْنُ يَحْيَى، حَدَّثَنَا سَعِيدُ بْنُ مُحَمَّدٍ الْجَرْمِيُّ، حَدَّثَنَا الْمُطَّلِبُ بْنُ زِيَادٍ، عَنْ إِسْحَاقَ بْنِ إِبْرَاهِيمَ، عَنْ جَدِّهِ، عُمَيْرٍ - وَهُوَ مَوْلَى ابْنِ مَسْعُودٍ - أَنَّ عَبْدَ اللَّهِ، قَالَ لَهُ يَا عُمَيْرُ إِنِّي أُعْتِقُكَ عِتْقًا هَنِيئًا إِنِّي سَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ ‏ "‏ أَيُّمَا رَجُلٍ أَعْتَقَ غُلاَمًا وَلَمْ يُسَمِّ مَالَهُ فَالْمَالُ لَهُ ‏" ‏ ‏.‏ فَأَخْبِرْنِي مَا مَالُكَ ‏.‏