This is it that the Lord spake; though the express words be not recorded in Scripture, where only the heads of sermons are contained, yet it is probable they were uttered by Moses in God's name. Howsoever, the sense and substance of them is in many places. See Exodus 19:22, Exodus 29:43 Leviticus 8:35. I will be sanctified: this may note either,
1. Their duty to sanctify God, i.e. to demean themselves with such care, and reverence, and watchfulness, as becomes the holiness of the God whom they serve, and of the worship in which they are engaged; whence he leaves them to gather the justice of the present judgment for their gross neglect herein. Or,
2. God's purpose to sanctify himself, i.e. to declare and manifest himself to be a holy and righteous God by his severe and impartial punishment of all transgressors, how near soever they are to him. In them that come nigh me, i.e. who draw near to me, or to the place where I dwell, and are admitted into the holy place, whence others are shut out. It is a description of the priests. See Exodus 19:22 Leviticus 21:7 Ezekiel 42:13,14. Before all the people I will be glorified: as they have sinned publicly and scandalously, so I will vindicate my honour in a public and exemplary manner, that all men may learn to give me the glory of my sovereignty and holiness by an exact conformity to my laws. Aaron held his peace, partly through excessive grief, which is sometimes signified by silence, as Isaiah 47:5 Lamentations 2:10, and principally in acknowledgment of God's justice and submission to it. Compare Psalms 39:10 Ezekiel 24:17. He murmured not, nor replied against God, nor against Moses; wisely considering that their sin was directly against God, and in that which is most dear and honourable in God's account, to wit, in his worship; and that God's honour ought to be dearer to him than his sons; and that this being the first violation of the law newly given, and committed by those who should have been the strictest observers and assertors of it, did deserve a very severe punishment.