Sahih Muslim 1226 b
This hadith been narrated on the authority of Jurairi with the same chain of transmitters, and Ibn Hatim said in his narration:
" A person said according to his personal opinion, and it was Umar."
وَحَدَّثَنَاهُ إِسْحَاقُ بْنُ إِبْرَاهِيمَ، وَمُحَمَّدُ بْنُ حَاتِمٍ، كِلاَهُمَا عَنْ وَكِيعٍ، حَدَّثَنَا سُفْيَانُ، عَنِ الْجُرَيْرِيِّ، فِي هَذَا الإِسْنَادِ وَقَالَ ابْنُ حَاتِمٍ فِي رِوَايَتِهِ ارْتَأَى رَجُلٌ بِرَأْيِهِ مَا شَاءَ ‏.‏ يَعْنِي عُمَرَ ‏.‏