Brass

which is an alloy of copper and zinc, was not known till the
thirteenth century. What is designated by this word in Scripture
is properly copper (Deut. 8:9). It was used for fetters (Judg.
16:21; 2 Kings 25:7), for pieces of armour (1 Sam. 17:5, 6), for
musical instruments (1 Chr. 15:19; 1 Cor. 13:1), and for money
(Matt. 10:9).

It is a symbol of insensibility and obstinacy in sin (Isa.
48:4; Jer. 6:28; Ezek. 22:18), and of strength (Ps. 107:16;
Micah 4:13).

The Macedonian empire is described as a kingdom of brass (Dan.
2:39). The "mountains of brass" Zechariah (6:1) speaks of have
been supposed to represent the immutable decrees of God.

The serpent of brass was made by Moses at the command of God
(Num. 21:4-9), and elevated on a pole, so that it might be seen
by all the people when wounded by the bite of the serpents that
were sent to them as a punishment for their murmurings against
God and against Moses. It was afterwards carried by the Jews
into Canaan, and preserved by them till the time of Hezekiah,
who caused it to be at length destroyed because it began to be
viewed by the people with superstitious reverence (2 Kings
18:4). (See NEHUSHTAN T0002700.)

The brazen serpent is alluded to by our Lord in John 3:14, 15.
(See SERPENT T0003287.)