The Messenger of Allah ﷺ stood in prayer, and we stood with him. An Arabi said while in the prayer, "Allah, have mercy on me and on Muhammad, and do not grant mercy along with us to anyone else."When the Prophet ﷺ concluded the prayer, he said to the Arabi, "You have restricted something vast," meaning the mercy of Allah.
قام رسول الله ﷺ في صلاة، وقمنا معه، فقال أعرابي وهو في الصلاة: اللهم ارحمني ومحمدا، ولا ترحم معنا أحدا فلما سلم النبي ﷺ قال للأعرابي: لقد حجرت واسعا يريد رحمة الله.