And Aaron took as Moses commanded and ran into the midst of the congregation; and behold, the plague was begun among the people: and he put on incense and made an atonement for the people. – Numbers 16:47

Wrath had gone out from God against the people on account of their sin, and it is God’s law that His wrath shall never stay unless a propitiation is offered. The incense which Aaron carried in his hand was the propitiation before God, from the fact that God saw in that perfume the type of that richer offering which our Great High Priest is this very day offering before the throne.

Aaron as the propitiator is to be looked at first as bearing in his censer that which was necessary for the propitiation. He did not come empty-handed. (As) God’s high priest, he must take the censer, he must fill it with the ordained incense, made with the ordained materials, and then he must light it with the sacred fire from off the altar, and with that alone. With the censer in his hand he is safe, without it Aaron might have died as well as the rest of the people. The qualification of Aaron partly lay in the fact that he had the censer, and that that censer was full of sweet odors which were acceptable to God.

Behold then, Christ Jesus as the propitiator for His people. He stands this day before God with His censer smoking up towards heaven. Behold the Great High Priest! See Him this day with His pierced hands, and head that once was crowned with thorns. Mark how the marvelous smoke of His merits goes up forever and ever before the eternal throne. ’Tis He, ’tis He alone who puts away the sins of His people. ~ C.H. Spurgeon

The High Priest Standing Between the Dead and the Living