I can't speak for non-Catholic Christians, but I do know that the very definition of sin in Catholicism involves the will. Things that are unwilled cannot, by definition, be imputed to you as personal sin. Therefore things that you dream, or unbidden thoughts suggesting sin but which you struggle against, or something done by a mentally incapacitated person, cannot be sins, though they be contrary to the Moral Law. On the other hand, even willfully entertaining the thought of illicit sex, or revenge, or murder, or humiliating somebody else, is a sin, because it is cooperation with the corruption of the will. Pleasurably thinking of it is a sin; actually planning it is even a worse sin, even if you don't actually carry it out. Intentionally fantasizing or planning are considered interior acts.
Jesus speaks of these things in the Sermon on the Mount. I hadn't realized that that was also in the Hebrew Scriptures, but that's great. I'm interested. Can you give me a chapter and verse?
Delighted when Jesus turns out to be (no surprise!) a good Jew.
I know it’s a bit late, but in answer to your question for proof-text, I was racking my brain— I know it from a lecture on Jewish philosophers, in this case, Rabbi Moses ben Maimon, Maimonedes, RaMbaM [his Jewish acronym.] But I heard it in seminary 9 years ago. So I knew that wouldn’t satisfy the root of your question (text.)
But, as divine providence guides us, in another FR post I was drawn back to a site hosting lectures on Judaism called simpletoremember.com. One of the lecturers, Lawrence Keleman, has a class on an unrelated topic (the proof of Jewish Oral tradition...) but in the first 13 minutes of it he builds up to and answers the question, from scripture, of where in the Torah we know that Nurture (particularly Divine nurturing through the commandments) can overcome Nature-— Genesis 1:1.... take a listen. As a grammatical guide, when he says “Bereishis” [the first word in the Hebrew Torah] is in construct state, he means that the Bi [prefix for “in”] is connected to reishis... “reishis” [”beginning of_”] in and of itself is the form of the word ree-shone [first] that needs, grammatically, to be adjunct to another word, ie: “beginning of_”time; “beginning of_”days; “beginning of_”our story. To say bireishis.... [bara— He created] leaves out an object of the construct state “beginning of.” Thus rendering it, literally: In the beginning of [missing object] G-d created. I know this is clumsy so see if Rabbi Keleman states it more clearly. He’s also pretty entertaining in a So Cal kind of way...
http://www.simpletoremember.com/media/a/Rational_Approach_Divinity_Oral_Tradition-B/