Sahih
Muslim
صحيح مسلم
38
The Book of Manners and Etiquette
كتاب الآداب
Chapter 1: The Prohibition Of Taking The Kunyah Abul-Qasim, And The Names Which Are Recommended
باب النَّهْىِ عَنِ التَّكَنِّي، بِأَبِي الْقَاسِمِ وَبَيَانِ مَا يُسْتَحَبُّ مِنَ الأَسْمَاءِ .
Sahih Muslim 2133 e
This hadith has been reported on the authority of A'mash with the same chain of transmitters but there is a slight variation (of wording) that, instead of the word Bu'ithat (I have been sent), the word ju'ilat (I have been made) has been used.
وَحَدَّثَنَا أَبُو كُرَيْبٍ، حَدَّثَنَا أَبُو مُعَاوِيَةَ، عَنِ الأَعْمَشِ، بِهَذَا الإِسْنَادِ وَقَالَ " إِنَّمَا جُعِلْتُ قَاسِمًا أَقْسِمُ بَيْنَكُمْ " .
Grade: Sahih