One day Bahlool was going to Haroun's palace, but they coincidentally met each other. Haroun asked, “ Bahlool, where are you going?”
“I was going towards you.”
Haroun said, “I want to go to school so I can closely observe Ameen and Mamoon. If you want, you can also come with me.”
Bahlool agreed and went to school with Haroun, but at that time Ameen and Mamoon had gone outside with the teacher's permission.
Haroun asked particular questions about Ameen and Mamoon. The teacher said, “Ameen is the son of the chief of Arab women, Zubaydah, but he is very foolish and stupid. Contrarily, Mamoon is very understanding, intelligent, and full of dignity.”
Haroun said, “I don't believe you.”
The teacher put a piece of paper under the sheet of the place where Mamoon sat and a brick under Ameen's seat. A few moments later Mamoon and Ameen entered. As soon as they saw their father, they paid their respects and sat down at their places. Mamoon worriedly glanced at the ceiling, and looked to his right and left.
The teacher asked him, “What has happened to you that you are so worried?”
Mamoon answered, “From the time I left school till when I returned, either the floor got one (width of a) paper higher, or the ceiling got that much lower. Briefly, my seat is a piece of paper higher.”
Then the teacher asked Ameen, “Do you feel like that too?”
Ameen answered, “I don't feel anything at all.”
The teacher laughed, and sent the two outside again. After they left, he said to Haroun, “Thanks be to Allah that I proved my statement in front of you.”
The Khalifa said, “At least tell the reason why.”
Bahlool said, “If I get assurance of my life, I will narrate the reason.”
“I assure you. Tell whatever you know.”
Bahlool said, “There are two reasons why children are bright and intelligent. The first reason is that when a man and a woman meet with mutual love, then their child is clever, bright, and intelligent. The second reason is that when a man and a woman keep connections with (people of) different blood and race, then their child becomes wise, intelligent, and keen. This is exactly what has been experienced in the case of trees and animals; if a fruit tree is grafted with another fruit-bearing tree, then their offspring will be very delicious and refined. Also, if two animals; for example, a donkey and a horse, are bred together, then they have a mule, which is very strong, sharp, and smart.
Therefore, the lack of understanding in Ameen is because the Khalifa and Zubaydah are of one blood and lineage; but Mamoon is very bright and intelligent because his mother is of a different blood and family; and in this respect, very different from the Khalifa.”
The Khalifa laughed at Bahlool's answer and said, “You can't expect more than this from a lunatic.”
But the teacher believed Bahlool with all his heart.