Sayyiduna Ibn Abbas (may Allah be pleased with them both) narrated that a bowl of tharid was brought to the Prophet (peace and blessings be upon him), and he (peace and blessings be upon him) said: "Eat from its sides and do not eat from its middle, for the blessing descends in its middle."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 12238