Sayyiduna Salman (may Allah be pleased with him) narrated: I said: O Messenger of Allah! I have read in the Torah that the blessing of food lies in performing ablution (wudu) before it. The Messenger of Allah (peace and blessings be upon him) said: "The blessing of food lies in performing ablution before it and after it."
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 6071