After the death of Aaron’s two sons, when they drew near before the Lord [offered false fire] and died, [Lev. 10:1-2]
The Lord said to Moses, Tell Aaron your brother he must not come at all times into the holy of holies within the veil, before the mercy seat upon the ark, lest he die; for I will appear in the cloud on the mercy seat. [Heb. 9:7-15, 25-28]
The priests being warned by the death of Nadab and Abihu to approach to God with reverence and godly fear, directions are here given how the nearest approach might be made….. Within the veil none must ever come but the high priest only, and he but one day in the year.
But see what a blessed change is made by the gospel of Christ; all good Christians have now boldness to enter into the holiest, through the veil, every day [Heb. 10:19-20]; and we come boldly [not as Aaron must, with fear and trembling] to the throne of grace, or mercy seat [Heb. 4:16]…..
Now therefore we are welcome to come at all times into the holy place not made with hands.
Then Aaron must not come near at all times, lest he die; we now must come near at all times that we may live: it is [keeping our] distance only that is our death [Matthew Henry’s Commentary].