Ali ibn al-Hasan ibn Faddal, from Abd al-Rahman ibn Abi Najran, from Abdullah ibn Sinan, from Abu Abdillah: I (narrator) heard Imam عليه السلام saying: “The one observing seclusion for worship (al-mutakif) in Mecca may pray in whichever of its houses he wishes; it is the same for him whether he prays in the mosque or in its houses.” And Imam عليه السلام said: “Devotional seclusion (al-ukuf) is not proper in other than it, except that it be in the Mosque of the Messenger of Allah سبحانه وتعالى, may Allah سبحانه وتعالى bless him and his family, or in one of the mosques of congregation. And the one observing seclusion for worship must not pray in a house other than the mosque in which he observed seclusion for worship (itikaf), except in Mecca, for he observes seclusion for worship (yatakif) in Mecca wherever he wishes, because all of it is the Sanctuary of Allah سبحانه وتعالى. And the one observing seclusion for worship (itikaf) must not go out from the mosque except for a need.”