Authentic Supplication Number 214.

`Abdullah bin Busr  said: The Messenger  stayed as a guest with my father. He said: We,, thus brought close to him some food and "watbatan"(228), thus he ate from it, then, he was brought some dates, he would eat of them, and put seeds between his two fingers, bringing together his index and middle finger, then he was brought some drink, so he drank it, then he handed it to the person sitting to his right. He said: Then my father said as he took the bridle of his beast of burden: Petition Allah for us, so he said: 'Allahumma barik lahum fee ma razaqtahum, waghfir lahum, warhamhum (229).

(229) O' mu ilah bestow blessing for them in that which You have provided them, and forgive them, and have mercy on them.

Reported by Muslim and is #151 in The Authentic of Good Sayings.