John Gill Commentary Exodus 30

And you shall make an altar to burn incense upon
The Targums of Onkelos and Jonathan call it incense of spices, properly enough, for it was made of various spices; of which see (Exodus 30:34) and this was necessary on a natural and civil account, to remove those ill smells from the sanctuary, occasioned by the number of beasts continually slain in it; but chiefly on a religions account, to denote the acceptableness of the service of the sanctuary to God:

of shittim wood you shall make it :
of the same that the altar of burnt offering was made, which was covered with brass, but this with gold, as after related; of this sort of wood, (See Gill on Exodus 25:5) as this altar was a type of Christ, the shittim wood may respect his human nature; which wood, though it sprung out of the earth, was not common, but choice and excellent, and very strong durable, and incorruptible; and so Christ, though he was man made of an earthly woman in his human nature, yet was chosen out of the people, is the chiefest among ten thousand, and excellent as the cedars, the man of God's right hand, whom he made strong for himself; and though he died in it, he saw no corruption, he now lives, and will live for evermore; in which nature he acts the part of a Mediator, and intercedes for his people, and offers up their prayers, perfumed with the much incense of his mediation, to which this altar has a special respect.

A cubit shall be the length of it, and a cubit the breadth
of it, it shall be four square
It was one Jewish square cubit, which is in surface, according to Bishop Cumberland, three English square feet, and about forty-seven square inches. This may denote the solidity, perfection, and extensiveness of Christ's priesthood, it being unchangeable, firm, and lasting; and which passes not from one to another, and which makes something perfect, which the law and priesthood of Aaron could not, even perfects forever those who are sanctified.

It is very extensive; the virtue of it reaches to all the elect of God, from the beginning of the world to the end of it; not his sacrifice only, but his intercession, which is principally respected; that is made for all the people of God, in all places, and in all ages, and for all things for them, both for this life, and that which is to come.

and two cubits shall be the height of it ;
so that it was twice as high as it was long and broad. Christ, our interceding high priest, is made higher than the heavens.

the horns of it shall be of the same ;
made of the same wood as the altar itself. These were a sort of spires that rose up at the four corners of the altar; and the Targum of Jonathan paraphrases the words, ``and of it its horns shall be erect;'' which were chiefly for decoration and ornament; and may denote the honour and glory of Christ, as well as his power and ability to save, to the uttermost, all who come to God by him, or lay hold upon him, since he ever lives to make intercession.

And thou shalt overlay it with pure gold
Hence this altar is sometimes called the golden altar, (Numbers 4:11) (Revelation 8:3) this may figure the deity of Christ, whose head is as the most fine gold, and is in the divine nature, in the form of God, and is the brightness of his glory, and possessed of the same perfections; or rather the glorification of his human nature in heaven, where he is highly exalted, and the preciousness of his intercession, which is always powerful and prevalent, and the duration of it:

the top thereof, and the sides thereof, round about, and the horns
thereof :
all and each of them were covered with gold; this altar had a top, when the altar of burnt offering had none, but its hollow place was filled up with earth at every encampment; so Jarchi observes: this was not a grate, as the Vulgate Latin version renders it, for here were neither blood nor ashes to be let through; but it was a flat covering like the roof of a house, as the word signifies, on which was set a golden dish, with live coals and incense burning on them; and which, when burnt, was carried away: and the sides are the four sides of the frame, it being a square, or the two sides and two ends of it; and the horns, the four horns at each corner, all were covered with plates of gold; so that this altar was a richer and more excellent one than that of burnt offering;

and may signify the superior excellency of Christ's state of exaltation to that of his humiliation: in the latter, which the altar of burnt offering respected, he was made of no reputation, and became obedient to the death of the cross, yea, was made sin, and a curse for his people; but in the former, which the altar of incense respected, he was raised from the dead, and had glory given him; he was raised for the justification of his people, and was himself justified in the Spirit, ascended on high, was received into glory, sat down at the right hand of God, making continual intercession for his saints:

and thou shall make unto it a crown of gold round about ;
which was partly to keep from slipping what was put upon it, but chiefly for ornament; and plainly points at the exaltation of Christ in our nature in heaven, as our interceding high priest, where he is a priest upon his throne; and is crowned with glory and honour.

And two golden rings you shall make to it under the crown of
it
The crown was on the top of the altar, at the edge of it all around; and just underneath it were two rings of gold, two on each side:

by the two corners of it, upon the two sides of it you shall make
them ;
at each corner a ring, and at each side; the use of them follows:

and they shall be for places for the staves to bear it with ;
these rings were for the staves to be put into when the altar was to be carried from place to place, as it was in the wilderness, during the travels of Israel there; and this signifies that Christ never leaves his people; when they are in the wilderness he is with them, interceding for them, providing all things necessary for their food, safety, and protection, (Revelation 12:14) .

And thou shalt make the staves of shittim wood
Of the same wood the altar itself was made:

and overlay them with gold ;
as that was; these rings and staves may be an emblem of the precious ordinances of Christ, in which he grants his presence; and where he is held forth in different ages and places as the interceding high priest of his people, their advocate with the Father, pleading continually his propitiatory sacrifice in their favour.