Sayyiduna Bara’ (may Allah be pleased with him) narrates that we used to like to stand on the right side of the Messenger of Allah (peace and blessings be upon him) while praying, because he would turn his greeting of peace (salam) to his right side.
Hadith Referenceصحيح ابن خزيمه / جماع أبواب قيام المأمومين خلف الإمام وما فيه من السنن / 1564