Invocation
Before eating
إِذَا أَكَلَ أَحَدُكُمْ طَعَاماً فَلْيَقُلْ بِسْمِ اللَّهِ، فَإِنْ نَسِيَ فِي أَوَّلِهِ فَلْيَقُلْ بسمِ اللَّهِ فِي أَوَّلِهِ وَآخِرِهِ
When anyone of you begins eating, say: With the Name of Allah. And if you forget then, when you remember, say: With the Name of Allah, in the beginning, and in the end.
Abu Dawud 3/347, At-Tirmidhi 4/288. See Al- Albani's Sahih At-Tirmidhi
2/167.