הלכה אויף דברים 17:8

From the laws of the commandment is that which they, may their memory be blessed, said (Sanhedrin 87a), that even though one who transgresses that which the Sages explained about the words of the Torah, transgresses this negative commandment of “you shall not stray”; nonetheless a man does not have the designation of a rebellious judge — known in the Gemara at the end of Sanhedrin 89a, who is liable for the death penalty — until he disagrees with the Great Court (see Mishneh Torah, Laws of Rebels 3:5, 7), and that he is a sage that has reached [the level] of pronouncing decisions [and] is ordained like the [members of the] Sanhedrin, and that he disagrees with them on a matter the volitional transgression of which [brings] excision and the inadvertent violation of which [brings] a sin-offering, and he instructs to do according to his decision or [himself] does the act according to his decision, as it is stated (Deuteronomy 17:12), “who wantonly does” — and not that he only instructs. But if he is a student that has not reached [the level] of pronouncing decisions, and makes a decision; he is exempt, as it is stated (Deuteronomy 17:8), “If a matter is baffling to you” — one who only a baffling thing is beyond him. And so [too,] if he found them outside of the Compartment of Paved Stone (in the Temple) and he rebelled against them, he is exempt, as it is stated, “and you will arise and go up to the place” — teaching that the place causes (is a requirement for) the death penalty.