Sunan Ibn Majah, Volume 4, Book 29, Hadith 3276 (DarusSalam) ⓘ

It was narrated that Wathilah bin Asqa’ Al-Laithi said: “The Messenger of Allah took hold of the top of the Tharid and said: ‘Eat in the Name of Allah from its sides and leave the top, for the blessing comes from its top.’”

حَدَّثَنَا هِشَامُ بْنُ عَمَّارٍ، حَدَّثَنَا أَبُو حَفْصٍ، عُمَرُ بْنُ الدَّرَفْسِ حَدَّثَنِي عَبْدُ الرَّحْمَنِ بْنُ أَبِي قَسِيمَةَ، عَنْ وَاثِلَةَ بْنِ الأَسْقَعِ اللَّيْثِيِّ، قَالَ أَخَذَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ بِرَأْسِ الثَّرِيدِ فَقَالَ ‏ "‏ كُلُوا بِسْمِ اللَّهِ مِنْ حَوَالَيْهَا وَاعْفُوا رَأْسَهَا فَإِنَّ الْبَرَكَةَ تَأْتِيهَا مِنْ فَوْقِهَا ‏" ‏ ‏.‏