Silsilah Sahihah

Uqbah bin Mughira narrates from his great-grandfather Makharraq, he says: On the day of the Battle of Jamal, I met Sayyiduna Ammar (may Allah be pleased with him) and he was urinating in a horn. I said: If I have to fight with you, should I join you? He said: Fight under the flag of your own people, because the Messenger of Allah (peace and blessings be upon him) liked for a man to fight under the flag of his own people.