Detachment from
Feeling gives Immunity towards Suffering!

The Blessed Buddha once
explained this to some sick bhikkhus:
If one keen on mental training feels a pleasant feeling, he
understands:
"This impermanent pleasure is neither to be clung to,
nor indulged in."
If he feels a painful feeling, he also understands and observes:
"As this pain is transient, it is neither to be clung to, nor engaged in..."
If he feels a neither-painful-nor-pleasant feeling, he similarly notes:
"This passing neutral feeling is neither to be clung to, nor held in delight.."
When he feels a pleasant feeling, he feels it, as if detached from it!
When he feels a painful feeling, he feels it, as if detached from it!
When he feels a neutral feeling, he feels it, as if detached from it!
He feels all feelings as something remote, alien, and not belonging to him.
When he feels a feeling terminating with the body, he understands:
"I feel a feeling terminating with the body..." (all bodily feeling!)
When he feels a feeling terminating with life, he understands:
"I feel a feeling terminating with life..." (all mental feeling!)
He understands: With the breakup of this body, at the exhaustion of life,
any feeling, neither being delighted in, nor clung to, will cool down
right
then and there...
An oil lamp burns depending on the oil
and the wick, at
the
exhaustion of the oil and the wick, the burning flame
is extinguished
through lack
of fuel, exactly so
here, bhikkhus,
when a bhikkhu feels a
feeling terminating with
the body... or
terminating
with life...
He understands: With the breakup of this body, at
the very exhaustion of
this life, all that is felt, not being indulged in,
nor clung to,
will
vanish right
there and then... This - only this - is the end of
Suffering!


Pleasant feeling induces greed...
Painful feeling produces hate...
Neither-painful-nor-pleasant neutral feeling
causes neglect & thus generates ignorance...

All
states converges on Feeling (Vedanā):
https://What-Buddha-Said.net/drops/II/Three_Basic_Kinds_of_Feeling.htm
https://What-Buddha-Said.net/drops/II/Feeling_Causes_and_Effects.htm
https://What-Buddha-Said.net/drops/II/The_8_Aspects_of_Feeling.htm
https://What-Buddha-Said.net/drops/II/Bodily_and_Mental_Feeling.htm
https://What-Buddha-Said.net/drops/II/Detached_from_Feeling.htm
https://What-Buddha-Said.net/drops/II/Dependent_on_Contact.htm
https://What-Buddha-Said.net/drops/III/Focusing_on_Feeling.htm
https://What-Buddha-Said.net/drops/III/Analysis_of_Feeling.htm
https://What-Buddha-Said.net/drops/II/The_108_Feelings.htm
https://What-Buddha-Said.net/drops/II/Emotional_Storm.htm
https://What-Buddha-Said.net/drops/II/Latent_Feeling.htm
https://What-Buddha-Said.net/drops/IV/Five_Feelings.htm

The Buddhas are the very best
Doctors!
Source (edited extract):
The Grouped Sayings of the Buddha.
Samyutta Nikāya.
Book IV [211-3]
section 36: Feeling. Vedanā.
The Sick-Ward. 7.
http://store.pariyatti.org/Connected-Discourses-of-the-Buddha_p_1379.html
https://What-Buddha-Said.net/library/ati_website/html/tipitaka/sn/index.html