Muhammad bin Jafar wrote a letter to His Eminence, Imam Mahdi (a.s.) asking him about some religious problem. His Eminence (a.s.) replied as follows:
As for a question you asked about the prayer at the time of sunrise and sunset its reply is as follows: It is so that they say that the sun rises and sets between the two horns of Shaitan, then what is better than prayer that it may rub the nose of Shaitan on the earth? Therefore recite prayer at this time and rub the nose of Shaitan (humiliate him).
As for a question about that which has become endowed about us and that which is fixed for us, but inspite of this if its owner becomes needful of it, its reply is as follows: Till it has not been accepted, a transaction is allowed to be made invalid and one could spend from it. If it has been accepted it cannot be made invalid, whether he is needful of it or not.
As for that which you asked: that if someone is having something from our property and he spends it without our permission as if he is himself the owner and considers it permissible for himself. The reply to it is as follows: One who does thus is accursed and on the Day of Judgment we would be displeased with him. The Holy Prophet (S) has certainly said: “Anyone who considers a prohibited thing of my progeny as permissible is eligible for my curse and that of all the prophets. One who encroaches upon our rights is among those who are unjust upon us and the curse of Allah (SwT) is upon him. The Almighty Allah (SwT) says:
“Know that! The curse of Allah is upon the oppressors.”4
His Eminence, the Awaited Imam (a.s.) has replied to some queries regarding the Islamic practical law:
Prayer at the time of sunrise and sunset is considered lawful. And one, who says against it, is saying so without any proof. In the same way the saying that “The sun rises and sets between the two horns of Shaitan” has been told to be a joke because these things are nothing but a part of baseless and useless views and statements.
Regarding endowments, especially for the Ahlul Bayt (a.s.), before it is accepted, the endowment maker is allowed to retract it in the circumstances that he has not yet entrusted to them, he can spend from it and take it back. But if the endowment has already been accepted by them, he is not allowed to annul it and take it back, because he has made it a necessity and taking back a necessity is not correct and the Imamate jurisprudents have issued a decree based on this.
It is not lawful to spend from the property that belongs exclusively to the Ahlul Bayt (a.s.). Then if someone considers it lawful he is an oppressor and usurper.