I know our current definition, legally, of adultery, is a married person having sex outside of their marriage.
However, Jesus seems to be teaching that any sex outside of marriage is a breach of the 7th commandment, “Thou shalt not commit adultery.”
Each commandment cover sins in that category.
For example, “Thou shalt not steal,” covers refusal to work, moving someone’s boundary marker, refusing to tithe, as well as stuff like grabbing someone’s money.
“Thou shalt not commit adultery,” covers any unBiblical sex act, whether homosexual behavior, rape, fornication or bestiality or whatever.
That’s the general understanding: that the ten commandments is the condensed list for the sins far more elaborately described and condemned throughout Scripture.
“Jesus seems to be teaching that...”
How so? Why should we not take it literally? Is there not a danger of sliding into gnosticism if we assume what things mean? Why, if people can do that, would they not assume that other parts of the Bible are non-literal?
“Each commandment cover sins in that category.”
I’m don’t think you can find that in the Bible, that the 10 commandments are the superclasses of sins, and other sins come under those.