"I want to learn God's secret mysteries!" a man said to Abu Said.
Abu Said gave him a box. "Take this home with you. I will come tomorrow and reveal what's inside."
The man, however, couldn't resist. He opened the box as soon as he got home, and a mouse ran out, escaping before the man could catch it.
"I asked about God's secret mysteries, and instead you gave me a mouse!" the man shouted angrily at Abu Said the next day.
"I gave you a mouse," Abu Said replied, "to teach you what it means to keep a secret."
Inspired by: Under the Sufi's Cloak: Stories of Abu Said and His Mystical Teaching by Mohammad Ali Jamnia and Mojdeh Bayat
Notes: This story is on p. 98 of the book. You can find out more about Abu Said at Wikipedia.