“Imagination is the door through which disease as well as healing enters. Disbelieve in the reality of sickness even when you are ill; an unrecognized visitor will flee.”
Swami Sri Yukteswar
Birthday is May 10.
Keep in mind very few people can reach that level where existence of body and its illness is denied on thought
When you have back pain fur example and you go deep in meditation and forget body and are determined with the thought there is no pain when body awareness returns it can go away
Yukteshwar and Yogananda both did it when sick. But in both cases their Guru instructed them to do so
Yogananda and all other great saints refused to cure their body later in life when sick. That is a higher level of yoga.