Kashrus
This is why the Torah goes on to teach the halachos of kashrus in great detail. These laws are of critical importance for they pertain to our mouths - the vessels of connection with Hashem. The food we put inside them is akin to the korbannos on the mizbe’ach.
Speech
The Torah also discusses other aspects of the mouth, specifically, its propensity to utter lashon ha’ra. The pessukim go to great length in discussing the metzora who was not careful with the words that came out of his mouth. He used the kli that Hashem gave for positive connection for precisely the opposite purposes - to distance people one from another. His punishment is therefore swift, he is stricken with tzara’as and must undergo a strenuous purification process accompanied by many messages as to how important it is to talk correctly.
Why Not to the Rav?
With most halachos, in the event of a sha’ala, we go to a rav or a posek. But with regard to tzara’as we go to the Kohen. Why so?
The Zera Shimshon explains that the metzora’s actual question is about his speech. Since his speech is akin to the food that connects him with Hashem, just like the korbannos, the one to pasken must be the Kohen.
Then, having discussed how to perfect our connection to Hashem through our mouths and our korbannos, we return to Acharey Mos and the aftermath of the deaths of Nadav and Avihu. We then proceed with the korbanos.
