Is the one afflicted by intrusive thoughts excused, and should he disregard the doubt that occurs to him during prayer? If so, what is the ruling concerning someone who disregards his doubts, but then Satan comes to him and tells him that he is negligent?

The cure for obsessive thoughts is to ignore them and pay them no mind, and to strive against oneself in repelling them. Continue with your prayer, paying no heed to the obsessive thoughts, and do not interrupt any of your prayers or repeat them, no matter how numerous they become. For one who is afflicted by obsessive thoughts is not negligent as long as they are overcome by those thoughts.