Al-Bara' (May Allah be pleased with him) reported:
Whenever we performed Salat behind the Messenger of Allah ﷺ, we liked to be on his right side so that his face might turn towards us (at the end of the Salat). One day, I heard Messenger of Allah ﷺ supplicating, "O my Rubb! Shield me from Your Torment on the Day when You will gather (or said, 'resurrect') Your slaves."

[Muslim].

وعن البراء، رضي الله عنه قال: "كنا إذا صلينا خلف رسول الله ﷺ ، أحببنا أن نكون عن يمينه، يقبل علينا بوجهه، فسمعته يقول: "رب قني عذابك يوم تبعث - أو تجمع- عبادك". ((رواه مسلم)).