Commercial Transactions (Kitab Al-Buyu)
23/7. Chapter:
Regarding Giving A Little More When Weighing And Weighing For A Fee
Sunan Abi Dawud
حَدَّثَنَا ابْنُ أَبِي رِزْمَةَ، سَمِعْتُ أَبِي يَقُولُ، قَالَ رَجُلٌ لِشُعْبَةَ خَالَفَكَ سُفْيَانُ . قَالَ دَمَغْتَنِي . وَبَلَغَنِي عَنْ يَحْيَى بْنِ مَعِينٍ قَالَ كُلُّ مَنْ خَالَفَ سُفْيَانَ فَالْقَوْلُ قَوْلُ سُفْيَانَ .
Narrated Ibn Abi Rizmah: I heard my father say: A man said to Shu'bah: Sufyan opposed you (i.e. narrated a tradition which differs from your version). He replied: You racked my mind. I have been told that Yahya b. Ma'in said: If anyone opposes Sufyan, the version of Sufyan will be acceptable.
Reference : Sunan Abi Dawud 3338In-book reference : Book 23, Hadith 13English translation : Book 22, Hadith 3332