This subsection of Wikipedia's Two Truths article says that the "two truths" distinction is not made in the suttas, but that there are some "suttas of indirect meaning".
Two Truths > Origin and development > Early Indian Buddhism > Pali Canon
In the Pali canon, the distinction is not made between a lower truth and a higher truth, but rather between two kinds of expressions of the same truth, which must be interpreted differently. Thus a phrase or passage, or a whole sutta, might be classed as neyyattha or samuti or vohāra, but it is not regarded at this stage as expressing or conveying a different level of truth.
Nītattha (Pāli; Sanskrit: nītārtha), "of plain or clear meaning" and neyyattha (Pāli; Sanskrit: neyartha), "[a word or sentence] having a sense that can only be guessed". These terms were used to identify texts or statements that either did or did not require additional interpretation. A nītattha text required no explanation, while a neyyattha one might mislead some people unless properly explained:
There are these two who misrepresent the Tathagata. Which two? He who represents a Sutta of indirect meaning as a Sutta of direct meaning and he who represents a Sutta of direct meaning as a Sutta of indirect meaning.
If you diagree with these statements, please say so.
Or if you agree with these statements, then please explain again: what is "a sutta of indirect meaning" (either in your own words or by referencing someone else's explanation); and cite some illustrative example[s] of "a sutta of indirect meaning".
Also is there a specific, official, or famous commentary on the suttas where they're "classed" like that (i.e. classified or described as neyyattha or samuti or vohāra)?