Signs and Symbols in
Christian Art, by George Ferguson (Oxford University Press), describes the miter
as "a tall headdress worn by cardinals, archbishops, bishops and some abbots.
It is a liturgical hat and has a plain and simple form, as well as a more ornate and
precious form with emand stones."
The miter is a sign of authority. When worn at Mass, it is taken off for the eucharistic
prayer. The "horns" of the miter are reminders of the rays of light that came
from the head of Moses when he received the Ten Commandments and are also symbolic of
the Old and New Testaments.