Know that if there was no occasion between fasting and these actions that made it obligatory, or the actions for which it is substituted, it would not be valid to take its place, and that is that every fast is an expiation, which is our saying that it is obligatory and optional. Some of them are permissible for what was forbidden to him, and some are forfeited by him. And it was said to me, “When you learned about these days and their obligation, we have entrusted you to yourself in determining these occasions, and you are not alone, but everyone who knows about them until he knows them is prohibited from knowing about them if he learns about them by any means.” This prevented me from clarifying these matters. Occasions: It is obligatory to pay attention to the divine commands and divine signs to the people of this path .