Sahih al-Bukhari 1319
Sahih al-Bukhari · Book 23: Funerals (Al-Janaa'iz) · The rows for a funeral prayer
Narrated Ash-Shaibani:
حَدَّثَنَا مُسْلِمٌ ، حَدَّثَنَا شُعْبَةُ ، حَدَّثَنَا الشَّيْبَانِيُّ ، عَنِ الشَّعْبِيِّ ، قَالَ أَخْبَرَنِي مَنْ، شَهِدَ النَّبِيَّ صلى الله عليه وسلم أَنَّهُ أَتَى عَلَى قَبْرٍ مَنْبُوذٍ فَصَفَّهُمْ وَكَبَّرَ أَرْبَعًا. قُلْتُ مَنْ حَدَّثَكَ قَالَ ابْنُ عَبَّاسٍ رضى الله عنهما .
Ash Shu`bi said, "I was informed by a man who had seen the Prophet (ﷺ) going to a grave that was separate from the other graves and he aligned the people in rows and said four Takbir." I said, "O Abu `Amr! who narrated (that) to you"? He said, "Ibn `Abbas. "