Musannaf Ibn Abi Shayba 28:633

'Abd al-Rahim ibn Sulayman narrated to us, from Hajjaj, who said: Someone who heard al-Qasim mention to me narrated to me, that Salman ibn Rabi'ah al-Bahili went on a military expedition to Balanjar. He went on an expedition and sought the assistance of some of the polytheists against the polytheists. And he said: "Let the enemies of God carry [the burden of fighting] against the enemies of God."