Some jurists do not pray when they are ill.

The Shaykh : ... Some of the jurists, when they were seated or when illness forced them to sit, did not pray. You cannot say anything about it except that he is a righteous man, yet he does not pray in his state of illness. Why? Because this bomb of divine decree is standing in his mind: "I am now lying down, and it is difficult for me to perform wudu, and it is difficult for me to stand, bow, and prostrate, so I am slow and I am making up [the prayer]."
Abu Layla: All right, my Shaykh, I suggest to our brother Ali, with your approval of course, that he record a lecture on this issue for tomorrow at Dhuhr, after he has narrated [the story].The Shaykh : Mahmoud.

The Shaykh: This is not permissible, because you have demolished what you built.
Abu Layla: And I fear, my Shaykh, when he studies it.

The Shaykh: When he does not study it, you tell him, "Do you permit it? Perhaps you are busy, and so on. Learn diplomacy, O Abu Ahmad."
Abu Layla: I, my Shaykh, after his permission.

The Shaykh: After you feel that he has not agreed, you tell him, "It appears that you are busy and have an obstacle to our brother Ali speaking on the topic."
Abu Layla: My Shaykh, some notes regarding this topic of the prayer you mentioned, the prayer of fear or in war, if there is something, my Shaykh, that we should be aware of.

The Shaykh: Here, you haveThe Shaykh : Ali will give you a lecture on it.