Thomas Aquinas Commentary Hebrews 6:13-20

"For when God made promise to Abraham, since he could swear by none greater, he sware by himself, saying, Surely blessing I will bless thee, and multiplying I will multiply thee. And thus, having patiently endured, he obtained the promise. For men swear by the greater: and in every dispute of theirs the oath is final for confirmation. Wherein God, being minded to show more abundantly unto the heirs of the promise the immutability of his counsel, interposed with an oath; that by two immutable things, in which it is impossible for God to lie, we may have a strong encouragement, who have fled for refuge to lay hold of the hope set before us: which we have as an anchor of the soul, [a hope] both sure and stedfast and entering into that which is within the veil; whither as a forerunner Jesus entered for us, having become a high priest for ever after the order of Melchizedek." — Hebrews 6:13-20 (ASV)

Previously, the Apostle showed why he had confidence in them: because of the good they performed. Here, he shows that same confidence based on the promise made to the Patriarchs. He does two things: first, he mentions the promise, and second, he gives the reason for what he says (in verse 16).

Regarding the first point, he does three things:

1. He shows to whom the promise was made.
2. He shows that the way the promise was given was suitable (verse 13b).
3. He explains the effect of the promise (verse 15).

God made a promise to Abraham: “To Abraham and his seed were the promises made” (Galatians 3:16). The reason for this is that we adhere to God by faith; consequently, we obtain the promise by faith. The first example of faith was found in Abraham. This is because, first, he was the first to withdraw from associating with unbelievers—“Go from your country and your kindred and your father’s house” (Genesis 12:1)—and second, because he was the first to believe something that was beyond nature: “In hope he believed against hope” (Romans 4:18). Therefore, Genesis 15:6 says: “Abraham believed God, and it was counted to him as righteousness.” For he was the first to receive the seal of faith, namely, circumcision (Romans 4:11).

The way the promise was given was suitable for two reasons: first, because of the oath, and second, because of the words of the promise (in verse 14).

He says, therefore, that God, wishing to show that His promise is firm and stable, swore by Himself since He had no one greater by whom to swear: “The LORD is high above all nations” (Psalms 112:4). As it is written, “By myself I have sworn, says the LORD” (Genesis 22:16). In this, you have an example that an oath is not unlawful in itself, because Scripture does not attribute to God anything that is inherently a sin. For Scripture intends to direct and lead us to God: “Be imitators of God, as beloved children” (Ephesians 5:1). Nevertheless, frequent swearing is forbidden—“Let not your mouth be accustomed to swearing” ()—as are oaths taken in vain: “You shall not take the name of the LORD your God in vain” (Exodus 20:7).

Then, in verse 14, he shows the manner in which the promise was made. It is as if God says, “Do not believe me, unless I bless you.” A blessing refers to bestowing benefits: “The blessing of the LORD makes rich” (Proverbs 10:22). “I will multiply you” pertains to having numerous offspring. Both promises were made to Abraham, as is clear from Genesis 14 and 15.

The author repeats the words, “blessing, I will bless,” to signify both temporal and spiritual goods, as well as the continuation of His blessing. Alternatively, “blessing I will bless” could refer to the multitude of holy offspring, who are designated by the stars of heaven: “Look up to heaven and number the stars if you can. And he said to him: So shall your seed be” (Genesis 15:5). And “multiplying, I will multiply” could refer to the number of wicked and perverse children, who are designated by the sand of the seashore. A third interpretation is that “I will bless you” refers to the good things of grace, and “I will multiply you” refers to the good things of glory: “How great is the multitude of your sweetness, O Lord” (Psalms 30:20).

The effect of the promise was that Abraham, “having patiently endured, obtained the promise.” Patient endurance consists not only in doing something great but also in waiting a long time. Abraham had the promise, yet he never possessed even a foot of land, as it says in Acts 7:5. Furthermore, he had no offspring until his old age. But he still kept his hope: “As an example of suffering and patience, brothers, take the prophets who spoke in the name of the Lord” (James 5:10); “Look to Abraham your father and to Sarah who bore you” (Isaiah 51:2).

When the author says, “For people swear by something greater than themselves,” he states the reason for what was said before. In this regard, he does three things: first, he mentions a human custom; second, the reason behind it; and third, the fruit of the promise (in verse 18).

Two human customs are mentioned. The first concerns that by which one swears, and the second concerns the effect of an oath: “in all their disputes an oath is final for confirmation.” That by which one swears is greater, and reasonably so, for swearing is nothing more than settling a doubt. Therefore, just as in the sciences nothing is settled except by something more certain, so too, because nothing is more certain to people than God, one swears by Him as by something greater and more certain.

But sometimes one swears by the Son, who is considered less in His humanity, as when one says, “by Christ.” Or one might swear by a creature, as Joseph swore by the life of Pharaoh (Genesis 42:16). I answer that there are two ways of swearing by God. One is by simple attestation, as when one says, “By God, it is so.” This is to say, “God is my witness that it is as I say,” as in Romans 1:9: “For God is my witness, whom I serve with my spirit.” The other way is by execration. This occurs when something, such as one’s head or soul, is offered to God for vengeance if the statement is false. This is how the Apostle swore in 2 Corinthians 1:23: “But I call God to witness upon my soul.” This is as if to say, “I offer my soul as a pledge, for which I invoke God’s name.” This is a very solemn oath.

One swears by a creature not as a creature, but insofar as a sign of God’s power is resplendent in it. Since all authority is from God (Romans 13:1), when someone with authority over a group swears by it, he swears by God, whose power is reflected in that authority. This is how Joseph swore by the life of Pharaoh. This, therefore, is what the author means when he says people swear by one greater than themselves.

It should be noted that certain people should be kept from taking oaths. Those known to be perjurers should be prevented, because the greatest reverence is due to an oath, and it can be presumed from their past actions that they will not show it proper reverence. Likewise, children should not be compelled to take an oath before the age of puberty, because they do not yet have the perfect use of reason to know what reverence an oath requires. The same applies to persons of high station, because an oath is required of those whose words or actions are in doubt. It detracts from the honor of persons in high positions when one doubts the truth of what they say. Hence, the Decretals state that a priest should not take an oath for a trivial reason (q. 2, ch. 4).

However, the causes for which it is lawful to swear are as follows:

1. To strengthen peace, as Laban swore (Genesis 31:48).
2. To preserve one’s good name.
3. To pledge fealty, as vassals swore to their lord.
4. To ensure obedience is fulfilled when something honorable is commanded by a superior.
5. To obtain security.
6. To attest to a truth, which is how the Apostle swore: “God is my witness, whom I serve in my spirit” (Romans 1:9).

When the author says, “and an oath is final for confirmation,” he mentions the effect of an oath, which is to put an end to all controversy. Just as in the sciences one stops after reducing a proof to its first principles, so too in divine law, one stops when one comes to the first truth. This happens when the first truth is invoked as a witness: “The master of the house shall be brought to the gods and he shall swear” (Exodus 22:8). In this way, all questions and controversies are settled.

When the author says, “So when God desired to show more convincingly to the heirs of the promise the unchangeable character of his purpose, he guaranteed it with an oath,” he states the reason God chose to swear: to show the unchangeability of His promise. He says “wherein”—that is, by the fact that He “guaranteed it with an oath”—He desired to show this “more convincingly.” It was already abundant that He promised, but it was “more abundant” that He swore. He desired to show the unchangeability of His purpose to the “heirs of the promise”—that is, of the thing promised: “It is the children of the promise who are counted as offspring” (Romans 9:8).

Regarding things that proceed from God, two aspects must be considered: the way things come into being, and God’s counsel which causes them to come into being. God’s counsel is absolutely unchangeable: “My counsel shall stand, and I will accomplish all my purpose” (Isaiah 46:10). The outworking of events, however, can appear changeable. The Lord sometimes announces something according to the natural order of things, as in Isaiah 38:1: “Set your house in order, for you shall die, you shall not recover.” This was because the cause of his sickness was such that he should have died from it. Another example is in Jonah 3:4: “Yet forty days, and Nineveh shall be overthrown!” This was because it deserved destruction. In such cases, the prophecy is a threat, as explained in Jeremiah 18:7: “If at any time I declare concerning a nation or a kingdom, that I will pluck up and break down and destroy it, and if that nation, concerning which I have spoken, turns from its evil, I will relent of the disaster that I intended to do to them.”

Sometimes, however, something is announced according to God’s eternal counsel, and in that case, God never relents or retracts it: “And also the Glory of Israel will not lie or have regret, for he is not a man, that he should have regret” (1 Samuel 15:29). It should be noted that whenever God promises something under oath, it is a prophecy of predestination that reveals God’s eternal plan. Such a promise is absolutely unchangeable.

Then, in verse 18, he shows the fruit of the promise. First, he shows what that fruit is, and second, what follows from it (in verse 19).

The fruit of the promise is that our hope is certain. Therefore, he says we have “strong encouragement”—that is, firm encouragement—for our hope. This encouragement comes from two unchangeable things in which it is impossible for God to lie: first, from God Himself, who promises and does not lie—“God is not a man, that he should lie” (Numbers 23:19)—and second, from the oath, which provides a stronger confirmation of the truth.

It should be noted that just as sensual delight is a sense experience and memory of the past, hope is oriented toward the future: “No one who puts his trust in him will be overcome” ; “They who wait for the LORD shall renew their strength; they shall mount up with wings like eagles; they shall run and not be weary; they shall walk and not faint” (Isaiah 40:31).

We have this encouragement, we “who have fled for refuge to take hold of the hope set before us.” We have fled from the evils of the world and the onslaught of the enemy to seize this hope: “Lord, you have been our refuge” (Psalms 89:11); “The name of the LORD is a strong tower; the righteous man runs into it and is safe” (Proverbs 18:10).

When the author says, “We have this as a sure and steadfast anchor of the soul,” he shows that faith will obtain the promise, and he uses a simile. He compares hope to an anchor. Just as an anchor secures a ship in the sea, so hope secures the soul in God in this world, which is like a sea: “This is the great and wide sea” (Psalms 103:25). This anchor must be strong, like iron: “I know whom I have believed, and I am convinced” (2 Timothy 1:12). It must also be firm, so that it is not easily removed from the ship. Thus, a person should be held fast to that hope.

An earthly anchor is fixed in a low place, but the anchor of hope is fixed in the highest place: in God Himself. For nothing in the present life is so firm that the soul can be secure and at rest in it. As Genesis 8:8 says, the dove “found no place to set her foot.” Therefore, the author says that this hope enters “into the inner place behind the curtain.” The Apostle understands the present condition of the Church by the holy place in the tabernacle, but by the Most Holy Place, which was separated from the holy place by a veil, he understands the state of future glory.

Therefore, he desires that the anchor of our hope be fixed in that which is now veiled from our eyes: “From of old no one has heard or perceived by the ear, no eye has seen a God besides you, who acts for those who wait for him” (Isaiah 64:4); “Oh, how abundant is your goodness, which you have stored up for those who fear you!” (Psalms 30:20). Our forerunner, who has entered there, has fixed it for us. As it says in John 14:2, “I go to prepare a place for you,” and in Micah 2:13, “He who opens the breach will go up before them.”

Therefore, he says that Jesus has gone as a forerunner on our behalf within the veil and has fixed our hope there, as is said in the collect for the Vigil and the day of Ascension. Yet, because the high priest alone was permitted to enter within the veil (Leviticus 16), he says that Jesus has entered on our behalf, “having become a high priest forever after the order of Melchizedek.” Notice how elegantly the Apostle returns to his main theme. He had begun to speak of the priesthood and then digressed, but now he returns to it, as is clear.