Musnad Ahmad 907:239

'Abd al-Rahman ibn Mahdi narrated to us, Shu'bah narrated to us, from Simak ibn Harb, from Jabir ibn Samurah, who said: I heard the Prophet, peace and blessings of Allah be upon him—and he said once: I heard Jabir, meaning ibn Samurah—that the Prophet, peace and blessings of Allah be upon him, named al-Madinah "Tabah."