Exodus 30:9Meaning & Commentary from the Church Fathers

A propitiatory offering was made on the burnt-offering altar, and it was only after this sacrificial act of atonement and reconciliation that the people, through the high priest, were permitted to approach the altar of incense. It was at this point that their prayers, along with those of the community, could ascend to the Most High. The very fact that there was a restriction on bringing anything to the altar of incense underscores this significance.