See that ye refuse not him that speaketh, etc. He uses the same verb as before, when he said that the people entreated that God should not speak to them; but he means as I think, another thing, even that we ought not to reject the word destined for us. He further shows what he had in view in the last comparison, even that the severest punishment awaits the despisers of the Gospel, since the ancients under the Law did not despise it with impunity. And he pursues the argument from the less to the greater, when he says, that God or Moses spoke then on earth, but that the same God or Christ speaks now from heaven. At the same time I prefer regarding God in both instances as the speaker. And he is said to have spoken on earth, because he spoke in a lower strain. Let us ever bear in mind that he refers to the external ministration of the Law, which, as compared with the gospel, partook of what was earthly, and did not lead men's minds above the heavens unto perfect wisdom; for though the Law contained in it the same truth, yet as it was only a training school, perfection could not belong to it. [1]

Footnotes

1 - By "him that speaketh," is by some understood Christ, but more properly God, as his is the leading subject in the foregoing and the following verses. The words which follow are brief; and the first clause is explained more fully in chapter 10:28, and the second in chapter 1:2. God spake "on earth" by Moses, but "from heaven" by his son, who came from heaven, ascended into heaven and sent his spirit down from heaven. The comparison here is between speaking on earth and speaking from heaven; but included in this, as previously explained in the Epistle, are the agents employed. God in delivering the Law fixed on a place on earth, and then as it were descended and employed an earthly agent, a mere man as his mediator; but in delivering the gospel, he did not descend from heaven, but employed a heavenly agent, his own son; thus manifested the superiority of the Gospel over the law. And that God is meant throughout this verse is evident from the following verse, "Whose voice," etc. The passage may be thus rendered, -- "See that ye reject not him who speaketh; for if they escaped not who rejected him when speaking on earth, how much more shall not we, if we turn away from him when speaking from heaven?" We have no single word to express chrematizonta -- oraculizing, rendered by Doddridge, "giving forth oracles;" by Macknight, "delivering an oracle;" and by Stuart, "warning." But the best word we can adopt here is "speaking." -- Ed

See that ye refuse not - That you do not reject or disregard.
Him that speaketh - That is, in the gospel. Do not turn away from him who has addressed you in the new dispensation, and called you to obey and serve him. The meaning is, that God had addressed "them" in the gospel as really as he had done the Hebrews on Mount Sinai, and that there was as much to be dreaded in disregarding his voice now as there was then. He does not speak, indeed, amidst lightnings, and thunders, and clouds, but he speaks by every message of mercy; by every invitation; by every tender appeal. He spake by his Son Hebrews 1:1; he speaks by the Holy Spirit, and by all his calls and warnings in the gospel.
For if they escaped not - If they who heard God under the old dispensation, who refused to obey him, were cut off; notes, Hebrews 10:28.
Who refused him that spake on earth - That is, Moses. The contrast here is between Moses and the Son of God - the head of the Jewish and the head of the Christian dispensation. Moses was a mere man, and spake as such, though in the name of God. The Son of God was from above, and spake as an inhabitant of heaven. "Much more," etc.; see the notes on Hebrews 2:2-3; Hebrews 10:29.

See - Βλεπετε· Take heed, that ye refuse not him - the Lord Jesus, the mediator of the new covenant, who now speaketh from heaven, by his Gospel, to the Jews and to the Gentiles, having in his incarnation come down from God.
Him that spake on earth - Moses, who spoke on the part of God to the Hebrews, every transgression of whose word received a just recompense of reward, none being permitted to escape punishment; consequently, if ye turn away from Christ, who speaks to you from heaven, you may expect a much sorer punishment, the offense against God being so much the more heinous, as the privileges slighted are more important and glorious.

(13) See that ye refuse not him that speaketh. For if they escaped not who refused him that spake on earth, much more [shall not] we [escape], if we turn away from him that [speaketh] from heaven:
(13) The applying of the former comparison: If it were not lawful to condemn his word which was spoken on the earth, how much less his voice which is from heaven?

See that ye refuse not him that speaketh,.... Jesus, the Mediator of the new covenant, whose blood speaks better things than Abel, or than his blood and sacrifice: he was the speaker in the council and covenant of grace, that spoke for the elect; in the creation of all things out of nothing, that said, and it was done; in giving the law to the Israelites, in the wilderness, for he is the angel which spake to Moses in Mount Sinai, he spoke to God for the Old Testament saints, and was the angel of God's presence to them; he spoke in his own person, as the prophet of the church, in the days of his flesh; and he now speaks in heaven, by appearing in the presence of God for his people, and by presenting his blood, righteousness, and sacrifice; he speaks by his Spirit, in and to the hearts of his saints; and by his ministers in the Gospel, and the ordinances of it: nor should he be refused, as he is, when his Gospel is made light of, and neglected; when men excuse themselves from an attendance on it; when they will not hear it; or, when they do, and contradict and blaspheme, despise and reproach it, or leave off hearing it. Care should be taken that Christ is not refused in the ministry of the word; which may be enforced from the greatness and excellency of the person speaking, who is God, and not a mere man; from the excellency of the matter spoken, the great salvation: and the rather diligent heed should be had unto him, since there is a backwardness to everything that is spiritual and heavenly; and since Satan is vigilant and industrious to put off persons from hearing the Gospel, or to steal the word from them:
for if they escaped not who refused him that spake on earth: the Ethiopic version renders it, "who appeared to them on the mount"; that is, on Mount Sinai; meaning either God himself, who descended on the mount, and spoke the ten commandments to the children of Israel; or Christ, the Angel that spoke to Moses in it; or rather Moses himself, who was on the earth, and of the earth, earthly; who spake from God to the people, being their mediator; him the Jews refused, would not obey him, but thrust him away, Acts 7:39, though they promised to hear and do all that was said to them; wherefore they did not escape divine vengeance and punishment; their carcasses fell in the wilderness at several times, in great numbers, and were not suffered to enter into Canaan's land: much more
shall not we escape, if we turn away from him that speaketh from heaven; that is, Christ, who came from heaven originally; is the Lord from heaven; whose doctrine is from heaven; and who, having done his work, is gone to heaven; where he now is, and from whence he speaks; and from hence he will come a second time, as Judge of all. There have been, and are some, that turn away from him; from a profession of him, and his Gospel and ordinances, and draw back unto perdition; such shall not escape divine wrath and vengeance; the sorest punishment shall be inflicted on them; see Hebrews 10:29.

refuse not--through unbelief.
him that speaketh--God in Christ. As the blood of sprinkling is represented as speaking to God for us, Hebrews 12:24; so here God is represented as speaking to us (Hebrews 1:1-2). His word now is the prelude of the last "shaking" of all things (Hebrews 12:27). The same word which is heard in the Gospel from heaven, will shake heaven and earth (Hebrews 12:26).
who refused him--Greek, "refusing as they did." Their seemingly submissive entreaty that the word should not be spoken to them by God any more (Hebrews 12:19), covered over refractory hearts, as their subsequent deeds showed (Hebrews 3:16).
that spake--revealing with oracular warnings His divine will: so the Greek.
if we turn away--Greek, "we who turn away." The word implies greater refractoriness than "refused," or "declined."
him that speaketh from heaven--God, by His Son in the Gospel, speaking from His heavenly throne. Hence, in Christ's preaching frequent mention is made of "the kingdom of the heavens" (Greek, Matthew 3:2). In the giving of the law God spake on earth (namely, Mount Sinai) by angels (Hebrews 2:2; compare Hebrews 1:2). In Exodus 20:22, when God says, "I talked with you from heaven," this passage in Hebrews shows that not the highest heavens, but the visible heavens, the clouds and darkness, are meant, out of which God by angels proclaimed the law on Sinai.

See that ye refuse not. The whole Old Testament shows that those who refused to listen to God's message delivered by men did not escape. How can those escape then who refuse to listen to God's own Son?
Whose voice then shook the earth. At Sinai (Exodus 19:18).
But now he hath promised. See Haggai 2:6, which declares the removal of the heavens and earth at Christ's coming.
And this word, Yet once more. This means, says the apostle, that there is only one more shaking after the time of Haggai. It is not a material, but moral and spiritual event. It began when Christ came and will continue until all that is temporal or erroneous be removed and only the eternal remains. Among the things removed is the covenant of Sinai.
Wherefore we, etc. We Christians have received a kingdom which cannot be shaken and which is eternal. Hence should serve God with reverence and godly fear since we are called to so high an estate.
For our God is a consuming fire. Because, while God is very merciful and loving, he will not overlook willful disobedience, but will destroy those who despise his commandments.

Refuse not - By unbelief. Him that speaketh - And whose speaking even now is a prelude to the final scene. The same voice which spake both by the law and in the gospel, when heard from heaven, will shake heaven and earth. For if they escaped not - His vengeance. Much more shall not we - Those of us who turn from him that speaketh from heaven - That is, who came from heaven to speak to us.