عَن أبي أَيُّوب قَالَ: كُنَّا عِنْدَ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فَقُرِّبَ طَعَامٌ فَلَمْ أَرَ طَعَامًا كَانَ أَعْظَمَ بَرَكَةً مِنْهُ أَوَّلَ مَا أَكَلْنَا وَلَا أَقَلَّ بَرَكَةً فِي آخِرِهِ قُلْنَا: يَا رَسُولَ اللَّهِ كَيْفَ هَذَا؟ قَالَ: «إِنَّا ذَكَرْنَا اسْمَ اللَّهِ عَلَيْهِ حِينَ أَكَلْنَا ثُمَّ قَعَدَ مَنْ أَكَلَ وَلَمْ يُسَمِّ اللَّهَ فَأَكَلَ مَعَهُ الشَّيْطَانُ» . رَوَاهُ فِي شرح السّنة

We were with the Prophet when food was presented to him, and I never saw food which had greater blessing when we began to eat, or less when we finished. We asked God’s messenger how that was, and he replied, “We mentioned God’s name when we ate, then one who ate sat down without mentioning God's name and the devil ate with him.” It is transmitted in Sharh as-sunna.