Sayyiduna Jabir bin Abdullah (may Allah be pleased with them both) says: I travelled with the Messenger of Allah (peace and blessings be upon him) on a military expedition, and he (peace and blessings be upon him) was praying. I stood on his (peace and blessings be upon him) left. He (peace and blessings be upon him) took my hand and made me stand on his right side. Ibn Sakhr (may Allah be pleased with him) came and stood on his (peace and blessings be upon him) left. He (peace and blessings be upon him) made us stand behind him.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 5153