Musnad Ahmad 459:6

Haywah ibn Shurayh narrated to us, Baqiyyah narrated to us, Buhayr ibn Sa’d narrated to me, from Khalid ibn Ma’dan, from Ibn Abi Bilal, from Irbad ibn Sariyah, that he narrated to them that the Messenger of Allah (may Allah bless him and grant him peace) exhorted them one day after the morning prayer, and he mentioned it.