Two problems occupied my mind and I (i.e. Al-Ḥusayn b. Ẓarīf) wanted to write to Abū Muḥammad (al-Ḥasan al-‘Askarī) peace be on him, about them. I wrote to ask him about how when the one who would undertake (the Imamate for the rest of time) (al-qā’im) would undertake his office, he would give his judgements and how his assembly would be in which he gave judgements between the people.
I (also) wanted to ask him about something for the quotidian fever. I forgot to mention the fever.
The answer came: “You asked about the one who will undertake (the office of the Imamate for the rest of time) (al-qā’im). When he undertakes his office, he will give judgements among the people through his knowledge just as David judged without asking for evidence.
You wanted to ask about the quotidian fever but you forgot. Write on a paper and hang it over the person with the fever: O fire, be cold and a place of safety for Abraham (Surah Anbiya: 69).”
I wrote down that and hung it over the person with the fever. He woke up recovered.
(Kitab Al Irshad, Chapter on Imam Hasan Askari (a.s.)Al-Kāfī, I, 509, tradition no. 13)