ENOfficial
Sad said: "We returned during the Hajj with the Prophet (ﷺ) and some of us said that they had stoned (the Jamarat) with seven stones, and other said that they had done so with six, and no one denounced anyone else."
Source: sunnah.com
Other translations
Arabic
أَخْبَرَنِي يَحْيَى بْنُ مُوسَى الْبَلْخِيُّ، قَالَ حَدَّثَنَا سُفْيَانُ بْنُ عُيَيْنَةَ، عَنِ ابْنِ أَبِي نَجِيحٍ، قَالَ قَالَ مُجَاهِدٌ قَالَ سَعْدٌ رَجَعْنَا فِي الْحَجَّةِ مَعَ النَّبِيِّ صلى الله عليه وسلم وَبَعْضُنَا يَقُولُ رَمَيْتُ بِسَبْعِ حَصَيَاتٍ وَبَعْضُنَا يَقُولُ رَمَيْتُ بِسِتٍّ فَلَمْ يَعِبْ بَعْضُهُمْ عَلَى بَعْضٍ .
sunnah.com