Musnad Ahmad 33:69

Muhammad ibn Ja'far narrated to us, Shu'bah narrated to us, from 'Amr ibn Murrah, from Salim ibn Abi al-Ja'd, who said: I asked Jabir ibn 'Abd Allah about the Companions of the Tree. He said: "If we had been one hundred thousand, it would have sufficed us. We were one thousand and five hundred."