By the eternal priesthood of Christ the Levitical priesthood of Aaron is abolished, 1-6; and the temporal covenant with the fathers is abolished by the eternal covenant of the Gospel, 7-13.
1 Now of the things which we have spoken, this is the sum: we have such a high priest who is set on the right hand of the throne of the Majesty in the heavens, 2 A minister of the sanctuary and of the true tabernacle, which the Lord pitched, and not man. 3 For every high priest is ordained to offer gifts and sacrifices; therefore, it is of necessity that this man should have something also to offer. 4 For if he were on earth, he would not be a priest, seeing there are priests who offer gifts according to the law, 5 Who serve to the example and shadow of heavenly things, as Moses was admonished by God when he was about to make the tabernacle, for he says, "See that you make all things according to the pattern shown to you on the mountain." 6 But now he has obtained a more excellent ministry, by as much as he is also the mediator of a better covenant, which was established upon better promises.
7 For if that first covenant had been faultless, then no place would have been sought for the second.
8 For finding fault with them, he says,
"'Behold, the days come,' says the Lord,/
'when I will make a new covenant/
with the house of Israel/
and with the house of Judah,
9 Not according to the covenant/
that I made with their fathers/
in the day when I took them by the hand/
to lead them out of the land of Egypt,/
for they did not continue in my covenant,/
and I did not regard them,' says the Lord.
10 'For this is the covenant/
that I will make with the house of Israel/
after those days,' says the Lord./
'I will put my laws into their mind/
and write them in their hearts./
And I will be to them a God,/
and they shall be to me a people.
11 And they shall not each teach his neighbor/
and each his brother, saying, "Know the Lord,"/
for all shall know me,/
from the least to the greatest.
12 For I will be merciful to their unrighteousness,/
and their sins and their iniquities/
I will no longer remember.'"
13 In that he says, "A new covenant," he has made the first old. Now that which decays and grows old is ready to vanish away.
Matthew Henry Commentary - Hebrews, Chapter 8[➚]
[v.5] - Quoting Exodus 25:40 (LXX—paraphrased). See also, Exodus 26:30.
[v.6] - "by as much as he is also..." - This might be confusing to read at first glance. Here is an explanation from John Calvin's Commentary: "As he had before inferred the excellency of the covenant from the dignity of the priesthood, so also now he maintains that Christ's priesthood is more excellent than that of Aaron, because he is the interpreter and Mediator of a better covenant. Both were necessary, for the Jews were to be led away from the superstitious observance of rituals, by which they were prevented from advancing directly forward to the attainment of the real and pure truth of the Gospel. The Apostle says now that it was but right that Moses and Aaron should give way to Christ as to one more excellent, because the gospel is a more excellent covenant than the Law, and also because the death of Christ was a nobler sacrifice than the victims under the Law."
[v.8-12] - Quoting Jeremiah 31:31-34 (LXX—paraphrased).