Genesis 41:34

Take up the fifth part of the land. — Heb., let him fifth the land, that is, exact a fifth part of the produce. It has been supposed that it had been usual in Egypt to pay to the king a tithe of the crop, and the doubling of the impost would not press very heavily on the people in these years of extraordinary abundance. As the reason of the enactment would be made known, it would also induce all careful people to store up a portion of their own superabundance for future need. Subsequently, a fifth of the produce was fixed by Joseph permanently as the king’s rent.