Abu Hurairah said; The Messenger of Allah (May peace be upon him) 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 (May peace be upon him) uttered the salutation, he said to the Bedouin; you narrowed down a vast (thing). By this he meant the mercy of Allah. (Using translation from Abū Dāʾūd 882)
قَامَ رَسُولُ اللهِ ﷺ إِلَى الصَّلَاةِ وَقُمْنَا مَعَهُ فَقَالَ أَعْرَابِيٌّ وَهُوَ فِي الصَّلَاةِ اللهُمَّ ارْحَمْنِي وَمُحَمَّدًا وَلَا تَرْحَمْ مَعَنَا أَحَدًا فَلَمَّا سَلَّمَ النَّبِيُّ ﷺ قَالَ لِلْأَعْرَابِيِّ لَقَدْ تَحَجَّرْتَ وَاسِعًا يُرِيدُ رَحْمَةَ اللهِ