In the long poem of Sufi wisdom called The Conference of the Birds, Fariduddin Attar gives the following tale about the prophet Joseph and his jealous brothers.

When Joseph’s treacherous half-brothers decided to sell him to a passing caravan of merchants, they insisted upon drawing up a bill of sale, naming the slave being sold and the price. This was duly signed and sealed, and then they returned home, counting their money, and leaving Joseph and the deed of sale with the merchants.

Many years later, famine forced the brothers into Egypt in search of grain, where they were unknowingly received by Joseph, who had risen to become the vizier of the Pharaoh. They did not recognise him, but Joseph knew well who they were. At a certain point, the vizier said to them, “You can read Hebrew. We have a document that we cannot read, but perhaps you can tell us what it says.” And he unrolled before them the deed of sale.

When the brothers read the Hebrew characters that were written there, and saw their own seals, they turned pale and fell silent. “What shall we say?” they asked themselves. “If we read this record of our deed aloud, we certainly face our own end.”

Do you not see, asks Attar, that this tale applies to you? Surely only a donkey would fail to understand!