That his father gave a slave to a son of his. So he went to the Prophet ﷺ to have him witness it. He ﷺ said: 'Have you given a gift similar to this one to all of your sons?' He replied: 'No'. So he said: 'Then take him back.'"  

أَنَّ أَبَاهُ نَحَلَ ابْنًا لَهُ غُلاَمًا فَأَتَى النَّبِيَّ ﷺ يُشْهِدُهُ فَقَالَ أَكُلَّ وَلَدِكَ نَحَلْتَهُ مِثْلَ مَا نَحَلْتَ هَذَا قَالَ لاَ قَالَ فَارْدُدْهُ