Musnad Ahmad 523
Ibraheem bin Sa`d narrated:
My father narrated that his father said:  I was praying and a man passed in front of me; I tried to stop him but he insisted. I asked `Uthman bin `Affan (about that) and he said. It does not affect you, O son of my brother.
حَدَّثَنَا عَبْد اللَّهِ، حَدَّثَنَا سُوَيْدُ بْنُ سَعِيدٍ، حَدَّثَنَا إِبْرَاهِيمُ بْنُ سَعْدٍ، حَدَّثَنِي أَبِي، عَنْ أَبِيهِ، قَالَ كُنْتُ أُصَلِّي فَمَرَّ رَجُلٌ بَيْنَ يَدَيَّ فَمَنَعْتُهُ فَأَبَى فَسَأَلْتُ عُثْمَانَ بْنَ عَفَّانَ فَقَالَ لَا يَضُرُّكَ يَا ابْنَ أَخِي‏.‏