Genesis 41:34-36

Let Pharaoh take action to appoint overseers and officials over the land, and set aside one-fifth [of the produce] of the [entire] land of Egypt in the seven years of abundance. Let them gather [as a tax] all [of the fifth of] the food of these good years that are coming, and store up grain under the direction and authority of Pharaoh, and let them guard the food [in fortified granaries] in the cities. That food shall be put [in storage] as a reserve for the land against the seven years of famine and hunger which will occur in the land of Egypt, so that the land (people) will not be ravaged during the famine.”