Nazir 56: Links in the Chain

More on the counting of the nazir and R. Hisda's ruling. Plus, the impurity from a dead body - that would require shaving for a nazir - would be a violation if one entered the Temple. The transmission of the teachings of some details here is ascribed to specific heritage - a direct line of passage down from one to the next, without always mentioning all the people along the way. Also, the question of the source for the ritual impurity issues - is it a point of heritage, a transmitted halakhah? Or is it something that can be concluded logically?