We do not recite the blessings over the flame or over the fragrant spices of idolaters, nor over the flame or fragrant spices of the dead, nor over the flame or fragrant spices [placed] before an idol. We do not recite the blessing over the flame until benefit is derived from its light.

One who ate, and forgot and did not recite Bircas HaMazon, Beis Shammai say: He should return to his place and recite Bircas HaMazon. But Beis Hillel say: He may recite Bircas HaMazon in the place where he remembered. Until when can he recite Bircas HaMazon? Until the food in his stomach has been digested.