What is the absolutely specific characteristic of feeling? It is to experience. That is to say, in any experience, what we experience is the individual maturation of any positive or negative actions as its final result.Here, the experience of feeling is called maturation. This is said for the purpose of becoming aware of the fact that pleasant or unpleasant feelings arising in us are nothing more than the result of the maturation of our action.-Abhidarmasamuccaya
The lam rim chen mo states,
The infallibility of our actions means that, whether we be ordinary persons or exalted beings, any pleasure with its pleasant feeling tone which occurs in us or any feeling of relief as is felt in a cool breeze by those born in hell, starts from previously accumlated positive actions, for it is impossible for pleasure to come from negative actions. So also, every painful feeling, even if it may occur in a saintly person, comes from previously accumulated negative actions, for it is impossible for pain to come from positive actions.
These three feelings become six according to their division whether they occurphysically or mentally so that one has three physical feelings and three mental feelings. The difference between physical feelings and mental feelings is that physical feelings occur within the realm of the five sense perceptions while mental feelings are those which occur in the realm of thought.Therefore, pleasure and frustration do not originate without a cause nor do they originate from inappropriate causes such as the gods Vishnu, Shiva, or anyone else. From generally positive or negative actions come generally positive or negative feelings. The various shades of these feelings come from the intensity of positive or negative actions. In each case, the certainty that the relationship between one's action and its result is certain and infallible, with no irregularity whatsoever, is the right view heldd by all Buddhists and praised as the foundation of all that is bright.From negative actions come all frustrations
And also, all evil forms of life.
From positive actions come all happy forms of life,
And also, all happiness in every walk of life.-Ratnamala
What is feeling? It is three ways of experiencing -- pleasantly, unpleasantly, and indifferently. 'Pleasant' is that which one would like to feel again (when the original feeling is over). 'Unpleasant' is what one would like to get rid of when it is present. 'Indifferent' is where neither of these two desires occur.
-Pancaskandhaprakarana
Why do we talk about physical feeling as that which occurs within the realm of sense perception?
Since the skin covers the whole body from head to toe, feelings which originate in the realm of the other four sensory perceptions are also called physical feelings. If we further distinguish those six feelings as subjectivistic feelings and transpersonal feelings, we have an additional twelve which make up a total of eighteen. Subjectivistic feelings are those that are always on the level of thinking that they are my feelings, while the transpersonal feelings are those which are felt on the level of primal awareness which immediately understands that there is no abiding principle to which the self may be reduced.Darkness is everywhere just as the skin covers the whole body-Catuhsataka
You might ask how it is that those who have this primal awareness by which they immediately understand that the self is not an eternal entity, have painful feelings, since the transpersonal feeling just explained would be in the realm of frustration. Oh there are many reasons for this. For example-
Feeling classified according to the function of rejection and aiding is twofold:Even those Arhats who have rejected the belief that self is an eternal entity still suffer such unpleasant feelings as headaches as a result of their former actions.-Vinayasastra
The sustaining feeling of addiction occurs on the level of desiring sensuous things of this world. The sustaining feeling of realization is to turn away from being addicted to these things and occurs on the level of those thought processes which are summarized by the subject matter of the first meditative stage.1. A sustaining feeling of addiction
2. A sustaining feeling of realization
The division into two kinds of feelings is made here for the purpose of knowing how the strength of feeling itself may, on the one hand, bring to light an existing desire or bring about detachment from this addiction through the subject matter of meditative concentration.