I saluted him and he replied to my salutation and then asked me...

I saluted him and he replied to my salutation and then asked me: Why don’t you write a book regarding the occultation, so that your sadness and worries are removed? I said: O son of Allah’s Messenger, I have compiled a number of books about occultation. He said: Not in this style. I order you to compile a book on occultation and therein mention about the occultation of the prophets (peace be on them). After that, the Imam (a.s.) departed from there.

When I woke up, I began to weep, supplicate and express my humility till dawn break. In the morning, in compliance with the commands of the Proof of Allah, I began the compilation of this book. While I pray for the help of…