The Lord will appear Hebrew, Hath appeared. He speaks of the thing to come as if it were past, which is frequent in Scripture, to give them the more assurance of its taking place.
Related Commentaries of Leviticus 9:4
Leviticus 9:4
4 Also a bullock and a ram for peace offerings, to sacrifice before the LORD; and a meat offering mingled with oil: for to day the LORD will appear unto you.