Abu Hurairah said; The Messenger of Allah ﷺ got up for the prayer and we also stood up along with him. A Bedouin said said during prayer; O Allah, show mercy to me and to Muhammed and do not show mercy to anyone along with us. When the Messenger of Allah ﷺ uttered the salutation, he said to the Bedouin; you narrowed down a vast (thing). By this he meant the mercy of Allah.

حَدَّثَنَا أَحْمَدُ بْنُ صَالِحٍ، حَدَّثَنَا عَبْدُ اللَّهِ بْنُ وَهْبٍ، أَخْبَرَنِي يُونُسُ، عَنِ ابْنِ شِهَابٍ، عَنْ أَبِي سَلَمَةَ بْنِ عَبْدِ الرَّحْمَنِ، أَنَّ أَبَا هُرَيْرَةَ، قَالَ قَامَ رَسُولُ اللَّهِ ﷺ إِلَى الصَّلاَةِ وَقُمْنَا مَعَهُ فَقَالَ أَعْرَابِيٌّ فِي الصَّلاَةِ اللَّهُمَّ ارْحَمْنِي وَمُحَمَّدًا وَلاَ تَرْحَمْ مَعَنَا أَحَدًا فَلَمَّا سَلَّمَ رَسُولُ اللَّهِ ﷺ قَالَ لِلأَعْرَابِيِّ
" لَقَدْ تَحَجَّرْتَ وَاسِعًا " . يُرِيدُ رَحْمَةَ اللَّهِ عَزَّ وَجَلَّ .