Sahih Muslim , Book 12, Hadith 3970 (USC-MSA) ⓘ
Nu'man b. Bashir reported: My father conferred a gift upon me, and then brought me to Allah's Messenger to make him a witness (to it). He (the Holy Prophet) said: Have you given such gift to every son of yours (as you have given to Nu'man)? He said: No. Thereupon he (the Holy Prophet) said: Don't you expect goodness from them as you expect from him? He said: Yes. of course. He (the Holy Prophet) said: I am not going to bear witness to it (as it is injustice). Ibn Aun (one of the narrators) said: I narrated this hadith to Muhammad (the other narrator) who said: Verily we narrated that lie (the Holy Prophet) had said: Observe equity amongst your children.
حَدَّثَنَا أَحْمَدُ بْنُ عُثْمَانَ النَّوْفَلِيُّ، حَدَّثَنَا أَزْهَرُ، حَدَّثَنَا ابْنُ عَوْنٍ، عَنِ الشَّعْبِيِّ، عَنِ النُّعْمَانِ بْنِ بَشِيرٍ، قَالَ نَحَلَنِي أَبِي نُحْلاً ثُمَّ أَتَى بِي إِلَى رَسُولِ اللَّهِ صلى الله عليه وسلم لِيُشْهِدَهُ فَقَالَ " أَكُلَّ وَلَدِكَ أَعْطَيْتَهُ هَذَا " . قَالَ لاَ . قَالَ " أَلَيْسَ تُرِيدُ مِنْهُمُ الْبِرَّ مِثْلَ مَا تُرِيدُ مِنْ ذَا " . قَالَ بَلَى . قَالَ " فَإِنِّي لاَ أَشْهَدُ " . قَالَ ابْنُ عَوْنٍ فَحَدَّثْتُ بِهِ مُحَمَّدًا فَقَالَ إِنَّمَا تَحَدَّثْنَا أَنَّهُ قَالَ " قَارِبُوا بَيْنَ أَوْلاَدِكُمْ " .
also referenced under: Book 24, Hadith 24 (In-Book) & Hadith 1623 (Reference)