For this reason, Ahmad al-Sabti, son of the Commander of the Faithful Harun al-Rashid, used to fast six days of every Friday and busy himself with worship during them. If it was a Saturday, he would be particular about what he ate for the rest of the week, and this is how he was called al-Sabti. I met him while circumambulating on a Friday after the prayer, and I did not recognize him except that I denied him and his condition during the circumambulation. I did not see him jostling or jostling or penetrating the two legs without separating them, so I said, “This is an incarnate spirit without a doubt,” so I caught him and greeted him. He responded to me and his cattle, and a conversation and negotiation took place between me and him, and one of them was that I said, “Why did I designate Saturday for the work of the craft?” and he said, “Because God Almighty began.”