Albert Barnes Commentary Numbers 16:47-48

"And Aaron took as Moses spake, and ran into the midst of the assembly; and, behold, the plague was begun among the people: and he put on the incense, and made atonement for the people. And he stood between the dead and the living; and the plague was stayed." — Numbers 16:47-48 (ASV)

A striking proof of the efficacy of that very Aaronic priesthood which the rebels had presumed to reject. The incense offering which had brought down destruction when presented by unauthorized hands, now, in the hand of the true priest, is the medium of instant salvation to the whole people. Aaron by his acceptable ministration and his personal self-devotion foreshadows emphatically in this transaction the perfect mediation and sacrifice of Himself made by Christ.