The relationship between Master and Student is examined. It is considered rude for a student to give a ruling on Jewish law in his Master’s presence. More than rude, actually:
Raba ruled: In the presence of one's Master it is forbidden [to give a legal decision] under the penalty of death;
This is death at the “hands of Heaven.” Still, not very pleasant. But what happens if the Master is not around?
in his absence this is forbidden but the penalty of death is not incurred.
So it is, when one lives in the vicinity of the Master, it is wrong to give rulings. That is there should not be two competing authorities.
Is then no penalty of death incurred in his absence? Was it not in fact taught: R. Eliezer b. Jacob stated: The sons of Aaron died29 only because they gave a legal decision in the presence of their Master Moses.
This is the story of Aaron’s sons Nadav and Abihu who brought “alien fire” to the alter and were struck dead by a fire from Heaven:
What was the exposition they made? And the sons of Aaron the priest shall put fire upon the altar; (Lev. 1:7) although, they said, fire came down from heaven [to light the alter originally](Lev. 9, 24) it is nevertheless a religious duty to bring also some ordinary fire.
What was the sin of Nadav and Abihu according to this reading? Not that they brought the “alien fire” but that they offered a “ruling” (the text says we should ‘put a fire’, not heaven) while their father the High Priest was alive!
R. Eliezer, furthermore, had a disciple who once gave a legal decision in his presence. ‘I wonder’, remarked R. Eliezer to his wife, Imma Shalom, ‘whether this man will live through the year’; and he actually did not live through the year. ‘Are you’, she asked him,’a prophet?’ ‘I’, he replied: ‘am neither a prophet for the son of a prophet, but I have this tradition: Whosoever gives a legal decision in the presence of his Master incurs the penalty of death’.
More details are given about this story and those details are debated. Why are the details even given?
in order that it be not said that the whole story was a fable.