Narrated Sulaiman Ash-Shaibam:

I heard Ash-Sha'bi saying, "A person who was accompanying the Prophet ﷺ passed by a grave that was separated from the other graves told me that the Prophet once led the people in the (funeral) prayer and the people had aligned behind him. I said, "O Aba 'Amr! Who told you about it?" He said, "Ibn Abbas."

حَدَّثَنَا ابْنُ الْمُثَنَّى، قَالَ حَدَّثَنِي غُنْدَرٌ، قَالَ حَدَّثَنَا شُعْبَةُ، قَالَ سَمِعْتُ سُلَيْمَانَ الشَّيْبَانِيَّ، قَالَ سَمِعْتُ الشَّعْبِيَّ، قَالَ أَخْبَرَنِي مَنْ، مَرَّ مَعَ النَّبِيِّ ﷺ عَلَى قَبْرٍ مَنْبُوذٍ، فَأَمَّهُمْ وَصَفُّوا عَلَيْهِ. فَقُلْتُ يَا أَبَا عَمْرٍو مَنْ حَدَّثَكَ فَقَالَ ابْنُ عَبَّاسٍ.