What is the supplication reported from the Messenger of Allah (peace be upon him) at the time of breaking the fast and before commencing the meal?

It is Sunnah for both the fasting person and others to say "Bismillah" (in the name of Allah) before eating. Upon breaking their fast, the fasting person says: "Thirst has gone, the veins are moistened, and the reward is confirmed, if Allah wills." They also add: "O Allah, I ask You by Your mercy which encompasses all things, to forgive me." They may also say: "O Allah, for You I have fasted, and with Your sustenance I have broken my fast."