Greed.

Once day, having learned that the King of Fez was hunting lions in the neighborhood, they decided to invite him and his court, and killed a number of sheep in his honors.

The sovereign had dinner and went to bed. Wishing to show their generosity, they placed a huge goatskin bottle before his door and agreed to fill it up with milk for the royal breakfast.

The villagers all had to milk their goats and then each of them had to tip his bucket into the container. Given its great size, each of them said to himself that he might just as well dilute his milk with a good quantity of water without anyone noticing.

To the extent that, in the morning, such a thin liquid was poured out for the king and his court that it had no taste than the taste of meanness and greed.

Source: "Leo The African" by Amin Maalouf