Buddhadasa Bhikkhu included this set of paintings along with the following description in his book The Spiritual Theatre: A Legacy for Mankind. 

In one of the Buddha's previous lives as a Bodhisattva (Buddha-to-be), he was reincarnated as a Lord of Monkeys. He governed a large troop of monkeys living in the legendary Himavanta forest and was well-loved and highly respected by all the other monkeys. One day, the Monkey Lord was unfortunately captured by a hunter. Seeing that he was a rare and clever albino monkey, the hunter presented him to King Brahmadatta of Varanasi.

Kept in the King’s pleasant royal garden for decades, the Bodhisattva Monkey witnessed the human way of life and observed that people always argued and fought over money and valuable possessions.

As time passed, the King became impressed by the respectable conduct of the Bodhisattva Monkey and ordered the hunter to release him back into the forest. The noble Monkey Lord could now re-joins his troop, and all its members gathered at a hillock to welcome their beloved leader. They greeted him with joy and inquired about his absence and where he had been living. The noble Monkey Lord graciously shared his story with his troop but omitted some parts which he considered inappropriate.

His followers then asked enthusiastically, “Dear Lord, you must have gotten to know human beings very well. Please tell us how those humans in the city behave and live their lives.” The Bodhisattva Monkey refused, saying, “My dear followers, please do not ask me about the way humans behave. I do not wish to talk about this.” However, his curious troop persisted, and the Monkey Lord finally gave in. He began by telling them that the humans in the city were so obsessed with their possessions that all day and all night, he kept hearing them say, “My money! My gold!”

Upon hearing this, all the monkeys covered their ears with their hands and feet and begged their leader, “My Lord, please, please stop; we’ve heard enough. We shall never ever want to hear about humans again.” The whole troop jumped up wildly and ran at breakneck speed to the nearest stream to cleanse their ears of this disgusting story of humans in the city. Then, the monkeys urged one another to move their troop deeper and deeper into the forest in order to get as far away as possible from the stench of human beings. No one ever saw this troop of monkeys again.