Sahih Muslim 1623 f
Nu'man b. Bashir reported that his mother bint Rawaha asked his (Nu'man's) father about donating some gifts from his property to his son. He deferred the matter by one year, and then set forth to do that. She (Nu'man's mother) said:
I shall not be pleased unless you call Allah's Messenger (ﷺ) as witness to what you confer as a gift on your son. (Nu'man said): So father took hold of my hand and I was at that time a boy, and came to Allah's Messenger (ﷺ). and said: Allah's Messenger, the mother of this son (of mine), daughter of Rawaha wishes that I should call you witness to what I confer as gift to her son. Allah's Messenger (may pease be upon him) said: Bashir, have you any other son besides this (son of yours)? He said: Yes. He (the Holy Prophet) said: Have you given gifts to all of them like this? He said: No. Thereupon he (the Holy Prophet) said: Then call me not as witness, for I cannot be witness to an injustice.
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا عَلِيُّ بْنُ مُسْهِرٍ، عَنْ أَبِي حَيَّانَ، عَنِ الشَّعْبِيِّ، عَنِ النُّعْمَانِ بْنِ بَشِيرٍ، ح.
 وَحَدَّثَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ بْنِ نُمَيْرٍ، - وَاللَّفْظُ لَهُ - حَدَّثَنَا مُحَمَّدُ بْنُ بِشْرٍ، حَدَّثَنَا أَبُو حَيَّانَ التَّيْمِيُّ، عَنِ الشَّعْبِيِّ، حَدَّثَنِي النُّعْمَانُ بْنُ بَشِيرٍ، أَنَّ أُمَّهُ بِنْتَ رَوَاحَةَ، سَأَلَتْ أَبَاهُ بَعْضَ الْمَوْهِبَةِ مِنْ مَالِهِ لاِبْنِهَا فَالْتَوَى بِهَا سَنَةً ثُمَّ بَدَا لَهُ فَقَالَتْ لاَ أَرْضَى حَتَّى تُشْهِدَ رَسُولَ اللَّهِ صلى الله عليه وسلم عَلَى مَا وَهَبْتَ لاِبْنِي ‏.‏ فَأَخَذَ أَبِي بِيَدِي وَأَنَا يَوْمَئِذٍ غُلاَمٌ فَأَتَى رَسُولَ اللَّهِ صلى الله عليه وسلم فَقَالَ يَا رَسُولَ اللَّهِ إِنَّ أُمَّ هَذَا بِنْتَ رَوَاحَةَ أَعْجَبَهَا أَنْ أُشْهِدَكَ عَلَى الَّذِي وَهَبْتُ لاِبْنِهَا ‏.‏ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ يَا بَشِيرُ أَلَكَ وَلَدٌ سِوَى هَذَا ‏"‏ ‏.‏ قَالَ نَعَمْ ‏.‏ فَقَالَ ‏"‏ أَكُلَّهُمْ وَهَبْتَ لَهُ مِثْلَ هَذَا ‏"‏ ‏.‏ قَالَ لاَ ‏.‏ قَالَ ‏"‏ فَلاَ تُشْهِدْنِي إِذًا فَإِنِّي لاَ أَشْهَدُ عَلَى جَوْرٍ ‏"‏ ‏.‏