meat - A general term for food, which in this case consists of grain. Instead of measuring, it was necessary in extreme scarcity to weigh it Leviticus 26:26; Revelation 6:6.
Twenty shekels a day - The shekel contained about 220 grains, so that 20 shekels would be about 56 of a pound.
From time to time - Thou shalt receive and eat it at the appointed interval of a day.