SN 22.62: What is meant by "scope of language"?

Bhikkhu Sujato translates it here as "three scopes of language, terminology and descriptions". Bhikkhu Bodhi translates it here as "these three pathways of language, pathways of designation, pathways of description".

What are they? Basically, they are "was", "will be" and "is".

As applied to the five aggregates (of form, feeling, perception, volitional formations and consciousness), they are:

• Past: Passed, ceased, changed
• Future: Yet to manifest
• Present: Has become manifest

The Buddha says that virtually everybody agrees that these five aggregates are either yet to become manifest, have become manifest, or have ceased or changed, through the same language, terminology and description that they use.

Looking at other suttas in the linked suttas of SN 22, this simply reinforces the theme that the five aggregates are impermanent (anicca), and one should not cling to them. Clinging to the aggregates, having desire for the five aggregates and/or associating them to the self, is a cause of suffering.

The sutta also talks about other non-Buddhist philosophers and their use of these terms for the same context. Here, the Buddha implies that everybody uses the same language, terminology and description to express the fact that they can observe - that the five aggregates are impermanent. Thus, it is ludicrous to believe that there is something permanent (such as a self) in or of the five aggregates. It's also not sensible to think that the five aggregates do not exist - surely they exist, but they are impermanent and changing. It is also perilous to cling to something impermanent, thinking that it will last forever.

Concerning "no-cause, inaction, and nihilism" - the fact that the five aggregates do in fact exist, but are impermanent and changing, hint at a means of how karma and its consequences can work. So, it also doesn't make sense to reject karma and its consequences.

The Buddha is basically pointing out that what he teaches is closely tied to the obvious things that people, since ancient times, have observed, and expressed through their language, terminology and descriptions - that the five aggregates are impermanent.

Brahman Dhammadhatu, interested,

It's not sure of what Brahman actually thought that he likes to ask. Maybe he "just" placed some generosity with a reminder and food for reflections with it. So not sure if such kind of extension was expected at the time the question came into being, asking "What is (was) the message of this sutta?", possible meaning "how could it be understood, or should be taken upon".

The Buddha pointed in this Sutta 'simply', if seen, on an important aspect of right speech, mentioning that even the opponents of him did not use wrong speech in regard of what was, is and might be, since such could be 'easy' used that one gets refuted, as being no right speech, not speaking on "facts".

Practicing to hold firm on such, sacca, is of great benefit, since it requires to investigate relations and does not allow much of easy talk, talk that seems as taking phenomena as real and without causes and even puts cause behind effect. As householder Ruben possible tried to point out in his answer, such right speech and good considerations before speaking works well as reminder on the Dhamma, if this is already known, or have been heard, remembering it.

A sample, part of it, in regard of present (knowing) and the past (having seen) is found direct under right/wrong speech:

"There is the case where a certain person, abandoning false speech, abstains from false speech. When he has been called to a town meeting, a group meeting, a gathering of his relatives, his guild, or of the royalty, if he is asked as a witness, 'Come & tell, good man, what you know': If he doesn't know, he says, 'I don't know.' If he does know, he says, 'I know.' If he hasn't seen, he says, 'I haven't seen.' If he has seen, he says, 'I have seen.' Thus he doesn't consciously tell a lie for his own sake, for the sake of another, or for the sake of any reward. Abandoning false speech, he abstains from false speech. He speaks the truth, holds to the truth, is firm, reliable, no deceiver of the world. — AN 10.176

The future is seldom used aside in citing teachers, those who know cause and it's effect, and if mentioned proper.

How do investigations around the topic accrue today, if done maybe differently, in other circumstances?

(note that this question is not given for trade, stacks, exchange or entertainment, but for ones work trough faults to escape the wheel here and liberation)

Niruttipathā adhivacanapathā paññattipathā are made known.

The Sutta means everyone has to accept together with the fact of the past, future and present aggregates' arising and vanishing although some of them have wrong view in the relativity of those aggregates as no-cause, inaction, and nihilism.

The accepting is well known in everyone's mind without announcement or language.

This translation was translated follow to Thai version translation, which is a wrong translation.

There are 2 kinds of pa~n~natti: naamapa~n~natti and atthapa~n~natti.

The paali in this sutta is talking about atthapa~n~natti, but the translation was translated as naamapa~n~natti. It is a common mistake of Thai buddhist translation.

See Paññatti and compare between this sutta paali and Paññattiniddeso.

Clearly the past, present and future (was, is, will be) are all evident and incontestible (i.e., uncorrupted and without defilements). Therefore, this sutta implies that the corruption and defilements arise taking the past, present and future as other than what they are. Indeed, suffering arises when we take the past as the present (remorse or sadness). Or suffering arises when we take the past as the future (craving or aversion). Or suffering arises when we take the past or future as the present (delusion). Mixing up past, present and future is suffering.

Yet if one directly knows what was, is and will be:

He directly knows water … fire … air … creatures … gods … the Creator … Brahmā … the gods of streaming radiance … the gods replete with glory … the gods of abundant fruit … the Overlord … the dimension of infinite space … the dimension of infinite consciousness … the dimension of nothingness … the dimension of neither perception nor non-perception … the seen … the heard … the thought … the known … oneness … diversity … all … He directly knows extinguishment as extinguishment. But he doesn’t identify with extinguishment, he doesn’t identify regarding extinguishment, he doesn’t identify as extinguishment, he doesn’t identify that ‘extinguishment is mine’, he doesn’t take pleasure in extinguishment. Why is that? Because he has understood that relishing is the root of suffering, and that rebirth comes from continued existence; whoever has come to be gets old and dies. That’s why the Realized One—with the ending, fading away, cessation, giving up, and letting go of all cravings—has awakened to the supreme perfect Awakening, I say --MN1