With a book entitled Epistle to the Hebrews we would expect it to have a large concentration of references to the Old Testament, and we would not be disappointed. As George Guthrie puts it: “Its astute scholar has crafted what might be called the 'Queen' when it comes to the use of the OT in the NT. No NT book, with perhaps the exception of Revelation, presents a discourse so permeated, so crafted, both at the macro- and microlevels, by various uses to which the older covenant texts are put, and his appropriation of the text is radically different from the book's apocalyptic cousin.” Since the above is true, I will not even attempt to be thorough in the brief review below but instead concentrate on the more obvious references to the OT only.
Hebrews 1 Right off the bat we are confronted with an embarrassment of riches in that this chapter contains a string of no less than seven separate OT passages that are quoted. The opening citation formula in 1:5 states that these are all spoken by God. The passages, in order, are Psalm 2:7-8; II Samuel 7:14; Deuteronomy 32:43; Psalm 104:4; Psalm 45:6-7; Psalm 102:25-27; and Psalm 110:1. That last source is especially important for the author of Hebrews because it is referred to also in Hebrews 8:1; 10:12; and 12:2, all taken as a messianic prophecy. Notice that in choosing these OT passages, the author has covered all three divisions of the OT canon: Pentateuch, Prophets (the OT history books were counted among the Former Prophets), and the Writings.
Hebrews 2:2 This verse may seem to be a strange statement, but the idea that the angels were the intermediaries between God and Moses in giving the Ten Commandments is also found in Acts 7:53 (parenthetically, one of many reasons why I feel that Luke was the author of Hebrews – see post on Hebrews 1-2 for more).
Hebrews 2:6 This quote from Psalm 8:4-6 is introduced in an even stranger manner. It says,"Someone has testified somewhere..." Does this indicate that the author of Hebrews didn't really know enough about the Scriptures to be able to identify the author or the book it came from? More on this in a bit.
Hebrews 2:11-12 Now we are actually told that Jesus was the one speaking the words in Psalm 22:22 and Isaiah 8:17-18.
Hebrews 2:17 At this point we are introduced to the second major way in which the author alludes to the OT, not in direct quotations but as descriptions of OT characters, events, and rituals. In almost every case, these are shown to be only types of someone greater to come, namely Christ. This verse is the first reference to him as a superior High Priest. The concept is so important to the author that this image will appear again in 3:1; 4:14; 5:3-10; and 6:19-20.
Hebrews 3:2-6 Moses is cited as an example of faithfulness in this quotation from the Septuagint version of Numbers 12:7.
Hebrews 3:7-4:13 This quotation from Psalm 95:7-11 and associated commentary about God's promised rest is introduced by the words “The Holy Spirit says.” But the last verse of this Psalms passage is then repeated in 4:3 where it is introduced by “He (God) said.”
Hebrews 4:4-5 Verse 4 cites Genesis 2:2 using the formula “In one place it says.” However, this is followed by a quotation from Psalm 95:11 where it is introduced by “And again in this place,” as if it appeared in the same book.
Hebrews 4:7 utilizes the citation formula “God says through David” in order to introduce a passage from the Psalms.
Hebrews 4:8 Here we have an allusion to Joshua leading the people into the Promised Land.
Hebrews 5:4 Aaron is used as a type of Christ, who is a superior High Priest.
Hebrews 5:5 This is a passage referring to God the Father, but the author of Hebrews applies it to Christ instead.
Hebrews 5:6 This verse starts out “he [God] says also in another place,” followed by quotation of Psalm 110:4.
Hebrews 6:13-14 quotes from Genesis 22:16-18.
Hebrews 7:1-28 recounts the story of Abraham with Melchizedek, the latter being a type of Christ.
Verse 17 “It is attested of him” followed by Psalm 110:4
Verse 21 “the one[God] said to him " " " " " "
Hebrews 8:5 “Moses was warned” (Exodus 25:40)
Hebrews 8:8 “God says” (Jeremiah 31:31-34)
Hebrews 9:1-10 The tabernacle and its associated rituals are described and treated as a type of what was to come, utilizing Exodus 25-26.
Verse 8 “the Holy Spirit indicates”
Hebrews 10:1 contains the important principle “the law was only a shadow...not the reality.”
Hebrews 10:5 “Christ said” introduces the Septuagint version of Psalm 40:6-8b. In other words, David is speaking as the Son of David in this passage.
Hebrews 10:12-13 Again Psalm 110:1 is quoted, this time without any introductory citation formula.
Hebrews 10:15-17 paraphrases Jeremiah 31:33-34 and is said to be a testimony of the Holy Spirit.
Hebrews 10:30 This quotation from Deuteronomy 30:35-36 is introduced with “we know the one who said,” referring to God. Between them, verses 29-31 actually mention the three persons of the Trinity.
Hebrews 10:37-38 utilizes no introductory words in from of this first quotation from one of the Minor Prophets – Habakkuk 2:3-4.
Hebrews 11 is the famous faith passage giving the example of persecuted OT heroes from Abel on through the later prophets and even alluding to the martyrs of Hellenistic times.
Hebrews 12:5-6 The “exhortation” here actually comes from Proverbs 3:11-12.
Hebrews 16-21 cites the respective examples of Esau and Moses on Mt. Sinai.
Hebrews 12:26-27 is a quotation from Haggai 2:6 given without any introduction.
Hebrews 13:5-6 in a similar manner provide quotations from Joshua 1:5 and Psalm 118:6.
Hebrews 13:11-13 provide additional references to temple worship as types of Christ.
Conclusion
The several rather sloppy reference by the author to a quote being found “somewhere” or spoken by “someone” seemingly indicate that he was not very well acquainted with the OT writings at all, but nothing could be further from the truth. We need to couple this with the fact that the author only once even identifies who the quotation came from. And in that example (Heb. 4:7), he specifically states that it was God who was speaking through David. Thus, the human authors of the OT Scriptures are really of little importance to the author of Hebrews. Instead, the real authors are given over and over again as either God the Father, Christ, or the Holy Spirit – a very clear proof of the doctrine of the Trinity.