Ezekiel 44:20

44:20 “‘They must not shave their heads nor let their hair grow long; they must only trim their heads.

Leviticus 21:5

21:5 Priests must not have a bald spot shaved on their head, they must not shave the corner of their beard, and they must not cut slashes in their body.

Isaiah 7:20

7:20 At that time the sovereign master will use a razor hired from the banks of the Euphrates River, the king of Assyria, to shave the head and the pubic hair; it will also shave off the beard.