Musnad Ahmad 31:549

'Abd al-Razzaq narrated to us, Ibn Jurayj informed us, he said: al-Harith ibn 'Abd al-Rahman informed me, from 'Iyad ibn 'Abd Allah ibn Sa'd ibn Abi Sarh, from Abu Sa'id al-Khudri: "That the Prophet, peace and blessings of Allah be upon him, used to begin on the day of al-Fitr and the day of al-Adha with the prayer before the sermon. Then he would deliver the sermon, and his sermon would be the command regarding the expedition and the military detachment."