الْحَمْدُ لِلَّهِ الَّذِي أَطْعَمَنِي هَذَا، وَرَزَقَنِيهِ، مِنْ غَيْرِ حَوْلٍ مِنِّي وَلاَ قُوَّةٍ

Praise is to Allah Who has given me this food and sustained me with it though I was unable to doit and powerless.

Alhamdu lillaahil-lathee 'at'amanee haathaa, wa razaqaneehi, min ghayri hawlin minnee wa laa quwwatin.

Allah will forgive him for all previous sins

At-Tirmithi, Abu Dawud, and Ibn Majah. See also Al-Albani, Sahih At-Tirmithi 3/159.