The references to the Old Testament in Hebrews 12-13 show that the author did not arbitrarily employ Scripture. His use of passages from Exodus, Leviticus, Deuteronomy, Psalms, Proverbs, and Haggai show that he viewed Scripture as a storyline that applied to the unique situation of his audience in Christ.
(1) In Heb 12:5-6, he quoted Prov 3:11-12 in order to describe how God used the audience’s struggles to train them in following Christ. While the audience had to endure their estrangement from Judaism, the author wanted his friends to know that they were in the Lord’s care. He quoted Prov 3:11-12 in Heb 12:5-6, writing, “My son, do not take the Lord’s discipline lightly, or faint when you are reproved by Him; For the Lord disciplines the one He loves, and punishes every son whom He receives.” God was not disciplining them for sin, He was rather training them in the steps of Christ. While natural fathers discipline their children based upon what seems good to them, Hebrews says that God disciplines His children so that they can share in His holiness (Heb 12:10). The audience in view had need of endurance not because of what they had done wrong, but in view of what they might become—those who enjoy fellowship with Him outside the camp (Heb 13:13), those who have a share in the city to come (Heb 13:14).
(2) In Heb 12:20-21, the author quoted Exod 19:12 and Deut 9:19 to contrast the manner of God’s revelation in the old and new covenants. In Exodus 19, the Lord appeared on Mount Sinai with the result that the mountain burned, and the earth shook, frightening Israel. Before the Lord came down upon the mountain, the Lord warned Moses of what was about to take place and told Moses to warn the people against approaching the place of the Lord’s presence. God said, “Put boundaries for the people all around the mountain and say: Be careful that you don’t go up on the mountain or touch its base. Anyone who touches the mountain will be put to death” (Exod 19:12). Moses later trembled at the sight of the Lord’s fierce anger upon the congregation when they bowed to the golden calf (Deut 9:19; Exodus 32). The audience of Hebrews need not fear the Lord in this way. Because of the arrival of the new covenant in Christ, they had come to Mount Zion, the heavenly Jerusalem, to an assembly of the perfected; they enjoyed the sprinkled blood of Jesus that gave them access to God (Heb 4:14-16; 10:19-25; 12:21-24; 13:20-21). By these gifts, the audience had all they needed to abstain from idolatry.
(3) In Heb 12:26, the author quoted Hag 2:6 to illustrate God’s activity in the abrogation of the old covenant and the establishment of the new covenant. The prophet spoke God’s word of promise to the returned exiles, those whose temple was meager in comparison to Solomon’s day, those who were discouraged at their small place in the broader world of their day. Through Haggai, the Lord promised to shake the earth and bring the treasures of the nations to Judah so that they could build the temple into an edifice that would surpass even the glory of Solomon’s temple (Hag 2:6-9). The author of Hebrews employed the words of the prophet to show that in the shaking of heaven and earth, only that which is in heaven, only that which is not created—only that which is distinctly of Christ—will endure. Because the new covenant provided permanent access to God, the author urged his audience to endure their difficulties, saying, “Since we are receiving a kingdom that cannot be shaken, let us hold on to grace. By it, we may serve God acceptably, with reverence and awe; for our God is a consuming fire” (Heb 12:28-29).
(4) In Heb 13:5-6, the author quoted Deut 31:6 and Ps 118:6 to remind his audience that God would care for them in their time of financial need. Near the end of his life, Moses prepared Israel for their conquest of Canaan. Moses assured Israel that Joshua would lead them to follow the ways of the Lord just as he had done and exhorted the people to be strong knowing that the Lord would never leave them nor forsake them (Deut 31:1-6). In Psalm 118, the psalmist celebrated the Lord’s care for Israel in giving them victory over their foes. When the psalmist was in distress, he cried out to the Lord, “The LORD is for me; I will not be afraid. What can man do to me?” (Ps 118:6). The author of Hebrews linked Deut 31:6 and Ps 118:6 to portray God’s care for those who rely upon Him.
(5) In Heb 13:11, the author referenced Moses’ command that Israel take the bodies of sacrificed animals outside the camp to burn them as a prompt for his audience to identify with Jesus apart from the structures of Judaism. When the Lord established Aaron and his sons as priests for Israel, He commanded Moses to consecrate them by slaughtering a bull as a sin offering. After the blood of the bull was applied to the altar, Moses was to burn the bull’s hide and flesh outside the camp (Exod 29:1-14). On the Day of Atonement, the High Priest was to burn outside the camp the remains of the bull and goat sacrificed as sin offerings (Lev 16:27). The author of Hebrews read these commands in light of Jesus’ death outside the city walls of Jerusalem. His audience therefore needed to courageously leave behind the structures of their religion and offer to Jesus the sacrifice of praise, the fruit of lips that confess His name and bear His disgrace (Heb 13:13-15).