3,974. A Kohein Whose Hair Has Grown Long

Hilchos Bias HaMikdash 1:8

A kohein whose hair has grown long may not enter the area of the altar and inward. If he goes there and performs the service, he is subject to a divine death penalty, the same as an intoxicated kohein who serves. This is derived from Ezekiel 44:20-21: “None of the kohanim may drink wine; they may not shave their heads or let their hair grow long.” Just as those who drunk wine are subject to a divine death penalty, the same is true of those who let their hair grow long.

Hilchos Bias HaMikdash 1:9

The service of a kohein who let his hair grow long is not invalidated. Even though he is subject to a divine death penalty, the service remains valid.