The Buddha explains how each of the five forces (that of pleasure, that of pain, that of mental ease, that of mental discomfort and that of detachment) is to be understood in it's arising, in it's settling down and in the escape from it.
Read the Sutta
There is some discussion of this sutta centering on the question: How is it that this sutta speaks of ending domanassa in the second jhana, when unwholesome states are spoken of as being gotten rid of to attain the first jhana?
The very first thing to understand here is that 'dukkha' or 'domanassa' or any of the other terms mentioned here are not the same things as 'Dukkh'indriyam', etc. The sutta is not speaking about 'dukkha', etc., it is speaking about 'dukkha-indriya' 'dukkha's force' or 'the force of dukkha'.
The second thing to understand is that the translation of 'indriya' as 'sense organ' or 'faculty' breaks down here. The Indriya are 'forces'; energy fields. How is 'dukkha' (pain) in any way a sense organ or faculty?
The next thing to understand is that neither pain nor the force of pain (or any of the other forces and their sources) are in-and-of-themselves unwholesome states. It is the personal reaction to the force that is the unwholesome state. The force can exist or appear to one without it being allowed to become an unwholesome state.
Again, to understand that this is not a corrupt sutta it must be understood that the Forces are not things in-and-of themselves. They are terms describing the potential of things which arise during jhana (or elsewhere) to disrupt the jhana or other aspects of one's practice.
'Force' describes the ability of a thing to affect one. Like 'horse-power'. The force of a hurricane (1,2,3,4) is not the wind or rain, it is the power of the wind or rain to cause damage. The force of an earthquake (5, 6, 7) is a measure of its ability to cause damage. It is not the actual shaking of the earth.
So the force of dukkha is not pain itself, but its potential to cause one to become upset, want to get away from it, or for it to otherwise disrupt one's ability to achieve freedom from pain. Rebirth has enormous potential to cause disturbance. Physical pain much less so.
These forces can enter your practice at any stage. You have been sitting in the first jhana, above unskillful states, for the past three hours and that pain in the ass that arises after such a time from the impression made there from the seam in your pants threatens to cause you to get up and do something else. Recognizing in the force of pain, its ability to disturb your sitting practice, knowing how it arises (from wanting to get rid of the pain itself), knowing how it ends (by ending the wanting), one has recognized and understood the force.
The work of entering the various jhana, the factors involved in attaining the jhanas, progressively eliminates the various forces as described in the sutta.
Though the pain may endure, it does not disturb.
The force of pain is to be got rid of in the first jhana; pain itself may not be got rid of before the fourth jhana, the unskillful state of being disturbed by the force is got rid of prior to the first jhana.
The force of misery (domanassa) is to be eliminated by the process of entering the second jhana, domanassa itself may not be eliminated before achieving the third jhana in the process of entering the fourth jhana, the unskillful state of being disturbed by the force is to be got rid of prior to the first jhana.
And it is the same with the other forces.
There are a number of other things we can learn from this sutta. The first is that we do not, as teachers of the Dhamma, need always to stick ridigidly to the precise order of the various lists of elements of the Dhamma. Here, for example, the usual order of this group of five Forces has been modified by Gotama so as to render it more in line with the experience and needs of the meditator. I suggest that the teacher who has a firm grip on his understanding of Dhamma should regard its various elements as tinker toys or pieces in an erector set, to be formed into a lesson as would best suit the student being instructed. Another thing that can be taken from this sutta is the understanding by the translator that not only do the various Pali Dictionaries represent translations, so that the definitions given in them and are suspect in themselves, but that the so-called 'original' Pali itself is a product of an editing that must have followed a translation of sorts for it's breaking up into words and sentenses (the earliest written documents ran-in all the words without breaks) and is also, therefore, subject to revision. A third thing we can learn is, when paying close attention to both translation and the Pali, the methodology of the translator can be seen. Difficulties are passed over, terminologies and phrasings from previous translations are adopted without careful consideration. Translations are derived from inference and logical reasoning where understanding through experience could be the only way a true meaning could be known. Etymologies which could go both forward and backward are taken to go in one direction only. And some things can now never be known with absolute certainty (for example the jhanas) because the only absolutely reliable authority (the Buddha, or one who learned directly from him) is long gone. I'm just saying! The Buddha tells us to beware of reliance on authority.
Exercise: Take this sutta and substitute the other 'authoritative' translations for the term 'Indriya' and think through the way these differences would change the entire practice:
Hare, Woodward: Controlling faculties, controlling powers,
Bhk. Bodhi, Rhys Davids, Bhk. Thanissaro, Walshe, Woodward: faculties.
Bhk. Thanissaro has an entire meditation course mapped out using 'faculties' as a translation for "Indriya".