Once a year Aaron shall purge its horns. Throughout your generations he is to purge it once a year with the blood of the atoning purification offering. This altar is most sacred to the Lord. Census Tax.
and again in the evening twilight, when he lights the lamps, he shall burn incense. Throughout your generations this shall be the regular incense offering before the Lord.
Aaron’s sons Nadab and Abihu took their censers and, putting incense on the fire they had set in them, they offered before the Lord unauthorized fire, such as he had not commanded.