Sahih al-Bukhari, Volume 8, Book 73, Hadith 39 (USC-MSA) ⓘ

Narrated Abu Huraira: Allah's Messenger stood up for the prayer and we too stood up along with him. Then a bedouin shouted while offering prayer. "O Allah! Bestow Your Mercy on me and Muhammad only and do not bestow it on anybody else along with us." When the Prophet had finished his prayer with Taslim, he said to the Bedouin, "You have limited (narrowed) a very vast (thing)," meaning Allah's Mercy.

حَدَّثَنَا أَبُو الْيَمَانِ، أَخْبَرَنَا شُعَيْبٌ، عَنِ الزُّهْرِيِّ، قَالَ أَخْبَرَنِي أَبُو سَلَمَةَ بْنُ عَبْدِ الرَّحْمَنِ، أَنَّ أَبَا هُرَيْرَةَ، قَالَ قَامَ رَسُولُ اللَّهِ صلى الله عليه وسلم فِي صَلاَةٍ وَقُمْنَا مَعَهُ، فَقَالَ أَعْرَابِيٌّ وَهْوَ فِي الصَّلاَةِ اللَّهُمَّ ارْحَمْنِي وَمُحَمَّدًا، وَلاَ تَرْحَمْ مَعَنَا أَحَدًا‏.‏ فَلَمَّا سَلَّمَ النَّبِيُّ صلى الله عليه وسلم قَالَ لِلأَعْرَابِيِّ ‏ "‏ لَقَدْ حَجَّرْتَ وَاسِعًا ‏" ‏‏.‏ يُرِيدُ رَحْمَةَ اللَّهِ‏.‏