Sanhedrin 63

Introduction: In the Talmud we have a statement of Rav that one who says to an idol "You are my god" is liable.
The Talmud asks liable for what? If the death penalty when he does it knowingly, then that is anyway what is says in the  Mishna. [Rav has told us nothing new and that is not good. He would not have just repeated the Mishna unless he would say that that is what he is doing.]
So he must have meant he is liable to bring a she goat [a sin offering]--the sacrifice prescribed by the Torah for doing idolatry by accident.
The Talmud asks that this does not seem to be like the Sages but only like Rabbi Akiva. [And that is not very good. We already know the law is not like Rabbi Akiva against more than one sage. If he would be arguing with only one other person that would be different.]
Where do you have this argument? In a Braita [teaching] that says:  One is liable to bring  a sin offering only for an act, e.g. bowing, pouring, burning, and sacrifice.

Reish Lakish said, "That is coming to Rabbi Akiva who said the law is one can be liable even when there is not a perfect act, but even just a small act like bowing."
The Gemara concludes that you have to say that the statement of Rav is coming only like Rabbi Akiva. (Even though the Talmud is obviously not happy with this.)

"So what might have we thought?", the Talmud continues. That being cut off from ones people is not written by idolatry. So now we know it is by means of a hekeih היקש -אתקושי אתקש-juxtaposition that God told Moses, "Go down from this mountain because the people gave sacrificed and bowed down and said these are your gods Oh Israel."

End of introduction.

So what is the obvious question here? It is that we start out not being happy with a obligation to bring a sin offering for speech. In the middle of the discussion we discovered that R.Akiva makes one liable even for bowing which is an act with no object.  So we decided that for speech also R Akiva would say one can be liable even though it is an act with no object.
But then look what happened. "We might have thought that כרת cutting off is not written by idolatry. So now we know it is by this juxtaposition. for idolatry.
We know you need an act to bring a sin offering because of Leviticus 4. ועשה אחת מהנה. And we know כרת  is written by idolatry in Numbers 16 where it gives the rules for the high priest,  the king, the congregation, and an individual to bring a sacrifice for idolatry. But there it is speech that is singled out. The verse says "This is the law for one who does by accident, but one who acts on purpose will be cut off from his people, he has blasphemed God." So what do we learn from the  היקש juxtaposition? That acts are also liable! Not just words.
So we learn from speech to acts. What the Talmud is trying to do is to learn from acts to speech. So what is going on? Could it be the Talmud is trying to answer for R. Akiva, and not Rav as it seems? Any suggestions?

)סנהדרין סג. הקדמה. רב אמר האומר לעבודה זרה אלי אתה חייב. התלמוד שואל חייב במה? אם מיתה זה כבר כתוב במשנה. אלא להביא קרבן חטאת. אבל אם זה נכון אז רב אמר משפטו רק לפי דעת רבי עקיבה שאמר בן אדם חייב גם על מעשה קטן למשל השתטחות. ומה היינו חושבים? שכרת אינו כתוב אצל עבודה זרה. קא משמע לן שיש היקש ויזבחו וישתחוו ויאמרו אלה אלהיך ישראל. סוף ההקדמה.השאלה כאן היא שהגמרא התחילה לשאול על דיבור. מפריע לגמרא שבן אדן יהיה חייב קרבן על דיבור. ואז היא מביאה פסוק שיש בו היקש בין דיבור ומעשה. זה אמור להורות שיש חיוב על דיבור. אבל קרבן ע''ז נכתב דווקא על דיבור