A'mash (may Allah have mercy on him) says: I asked Ibrahim, "If only one person is praying with the imam, what should he do?" He said, "He should stand on the left side of the imam." I mentioned to him the hadith of Sayyiduna Ibn Abbas (may Allah be pleased with them both) that the Prophet (peace and blessings be upon him) made him stand on his right side, so he accepted it.