In what Sutta(s) is there a References to Imagine the Body Inside Out and What is Below the Skin

Question

In a Sutta there is a reference to imagine the body inside out, in which case you will be chasing animals from pecking at you.

Also perhaps in the same Sutta or another you imagine what is beneath the skin.

What are these 2 references?

Answer 1

Could it be the Puttamansa Sutta: A Son's Flesh SN 12.63 that you are seeking?

In this Sutta, Buddha speaks of four kinds of nutriment: edible food, sense-impressions, volitions, and consciousness. Under Sense-impression there is this simile of a skinned cow that points out that wherever she stands, will be ceaselessly attacked by the insects and other creatures living in the vicinity.

"And how, O monks, should the nutriment sense-impression be considered? Suppose, O monks, there is a skinned cow that stands close to a wall, then the creatures living in the wall will nibble at the cow; and if the skinned cow stands near a tree, then the creatures living in the tree will nibble at it; if it stands in the water, the creatures living in the water will nibble at it; if it stands in the open air, the creatures living in the air will nibble at it. Wherever that skinned cow stands, the creatures living there will nibble at it.

"In that manner, I say, O monks, should the nutriment sense-impression be considered. If the nutriment sense-impression is comprehended, the three kinds of feeling are thereby comprehended. And if the three kinds of feeling are comprehended, there is, I say, no further work left to do for the noble disciple.

Like a skinned cow, man is helplessly exposed to the constant excitation and irritation of the sense-impressions, crowding upon him from all sides, through all six senses.

Answer 2

Sampasadanīya Sutta has the latter element but not the former.