Musnad Ahmad 459:7

Isma'il narrated to us, from Hisham al-Dastawa'i, from Yahya ibn Abi Kathir, from Muhammad ibn Ibrahim ibn al-Harith, from Khalid ibn Ma'dan, from Ibn Abi Bilal, from al-'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.