Musnad Ahmad 753:3

Sa'id ibn Mansur narrated to us, he said: Al-Mughirah ibn 'Abd al-Rahman narrated to us, from Abu al-Zinad, he said: Muraqqa' ibn Sayfi narrated to me, he said: My grandfather, Rabah ibn Rabi', the brother of Hanzalah the Scribe, narrated to me: "That he went out with the Messenger of Allah, may Allah bless him and grant him peace, on a military expedition, and at the vanguard of his army was Khalid ibn al-Walid." Then he mentioned Rabah and his companions, and he mentioned the rest of the hadith.