I’m looking for suttas addressing excessive concern about the body (as in health worry not concern about looks). edit: also anything regarding right view about the body will help
When Ven Assaji was sick, the Buddha went to see him. Their discussion is recorded in SN22.88
‘Sir, the mendicant Assaji is sick, suffering, gravely ill. He bows with his head to your feet.’ And then say: ‘Sir, please go to the mendicant Assaji out of compassion.’”
“Yes, reverend,” those monks replied. They did as he asked. The Buddha consented in silence.
SN36.7 has similar instructions on how to approach sickness.
And Ajahn Brahm spoke on this topic in “Have you come here to die?”
The Buddha says that without mindfulness regarding the body, Mara will gain an entry (MN 119), and that could be in the form of worry. The absence of mindfulness of the body will result in some hindrance filling the void. The sutta describes how to develop mindfulness of the body beginning with the breath, then the other exercises from the first foundation of mindfulness. A sick body is a good subject illustrating the impermanence of the body.
From SN 35.101:
“Suppose, bhikkhus, people were to carry off the grass, sticks, branches, and foliage in this Jeta’s Grove, or to burn them, or to do with them as they wish. Would you think: ‘People are carrying us off, or burning us, or doing with us as they wish’?”
4“No, venerable sir. For what reason? Because, venerable sir, that is neither our self nor what belongs to our self.”
5“So too, bhikkhus, the eye is not yours … Whatever feeling arises with mind-contact as condition … that too is not yours: abandon it. When you have abandoned it, that will lead to your welfare and happiness.”
The four steps of the first tetrad of the Anapanasati sutta (MN 118) instruct how to 1 & 2) gain familiarity with the breath, then 3) investigate its effects throughout the body. The breath supports life, and in normal circumstances a few minutes without it would be fatal. That means it is delivering life-giving energies to the bodily system, and awareness of this effect is necessary. The breath should become an energy that is felt. This prepares for the second tetrad where awareness of feelings is developed. Both tetrads conclude with calming, the cycle of energetic investigation followed by tranquillity being normal procedure in the suttas, for example in the seven factors of awakening.
Mind-states tend to focus themselves on particular parts of the body, and meditation on the breath locates consciousness in the chest area, then at times pervades the whole body. When developed, this purifies and excludes negative mind-body associations.
Mara’s entry is via the body:
“Now, suppose that there were an empty, hollow water-pot set on a stand, and a man were to come along carrying a load of water. What do you think — would he get a place to put his water?”
"In the same way, in whomever mindfulness immersed in the body is not developed, not pursued, Mara gains entry, Mara gains a foothold.
“Now, in whomever mindfulness immersed in the body is developed, is pursued, Mara gains no entry, Mara gains no foothold.”—MN 118