13and put the incense on the fire before the LORD, that the cloud of the incense may cover the mercy seat that is over the testimony, so that he does not die.
In Exodus 33:20, the Lord revealed that no one can see his face and live. The cloud prevented Aaron from seeing the presence of God. It was, in other words, for his protection.
13 and put the incense on the fire before the LORD, that the cloud of the incense may cover the mercy seat that is over the testimony, so that he does not die.