Musnad Ahmad 25:1331

'Abd al-Rahman and Ibn Ja'far narrated to us, they said: Shu'bah narrated to us, from 'Ata' ibn al-Sa'ib, from Sa'id ibn Jubayr, from Ibn 'Abbas: That the Prophet, peace and blessings of Allah be upon him, was brought a bowl of tharid (a dish of bread and broth). He said: "Eat from its surroundings, and do not eat from its middle, for the blessing descends into its middle." Ibn Ja'far said: "From its sides or from its edges."