(Imām Bukhārī narrates): Muslim narrated to us, he said: Shu'bah narrated to us, from Al-Hakam, from Dharr, from Ibn Abdur Rahman, from Abdur Rahman, he said:
I was with Hazrat Umar when Ammar said this to him, then he narrated the hadith.
حَدَّثَنَا مُسْلِمٌ، حَدَّثَنَا شُعْبَةُ، عَنِ الحَكَمِ، عَنْ ذَرٍّ، عَنْ ابْنِ عَبْدِ الرَّحْمَنِ، عَنْ عَبْدِ الرَّحْمَنِ بْنِ أَبْزَى
قَالَ: شَهِدْتُ عُمَرَ، فَقَالَ لَهُ عَمَّارٌ، وَسَاقَ الحَدِيثَ
Reference: Sahih Al Bukhari 342