Musnad Abu Ya'la al-Mawsili 118:24

Abu Khaythama narrated to us, Ibn 'Uyaynah narrated to us, from al-Zuhri, from Anas, that the Prophet (peace and blessings of Allah be upon him) held a wedding feast for Safiyyah. He (the narrator) said: I think he said with dates and sawiq (roasted barley/wheat flour).