In my sermon today, I summarized the flow of thought in Hebrews 3:7-19 like this:
1) The unbelief and hard hearts of the first-generation Israelites led them to lose out on the reward of rest.
2) Christian believers, likewise, can be deceived by sin, resulting in unbelief, hard hearts and loss of reward.
3) To avoid this, Christians must regularly encourage one another and hold firm their confidence in the Gospel.
The text I preached ended with the statement: “So we see that they were unable to enter because of unbelief” (Heb 3:19 ESV). The “they” here is the first-generation Israelites, those who died in the wilderness. They are those whom Psalm 95 speaks about, the psalm which is quoted here in Hebrews 3.
So Hebrews 3 quotes Psalm 95 and makes the point that “unbelief” stopped the first-generation Israelites from entering the Promised Land.
It appears that Hebrews 3 is drawing most of its points and terminology from this psalm. However, “unbelief” is never mentioned in Psalm 95. The psalm mentions hard hearts (vs 8), people going astray in their heart (vs 10) and people who have not known God’s ways (vs 10). But it does not mention the sin of “unbelief.”
Why does Hebrews 3 focus so much on that when it’s absent from the psalm?
The answer may be found in the psalm’s focus. Psalm 95 alludes back to two primary texts: Exodus 17 and Numbers 14. Exodus 17 is the story where the Israelites (after having just been given manna) quarrel with Moses since they have nothing to drink. God tells Moses to strike a rock, which he does, and out comes water. The place is renamed Massah and Meribah—Testing and Quarrelling—because of the sin of the people. Psalm 95 clearly alludes to this incident with the reference to Massah and Meribah, but Exodus 17 does not mention unbelief.
In Numbers 14, however, the emphasis appears explicitly.
There, the 12 spies have just come back from the Promised Land, with 10 of them reporting terribly frightening things about the Land, and 2 of them (Joshua and Caleb) acting on belief in God’s power to overcome any obstacles. Moses and Aaron are frustrated at the people’s lack of faith and appeal to God for help.
God says to Moses, “How long will they not believe in me?” (14:11 ESV, emphasis my own). Then, after Moses intercedes, stopping God from executing the entirety of the people immediately, God instead determines to let the first generation Israelites die in the wilderness over 40 years of time.
The unbelief of the people here in Numbers 14 is clear. So Hebrews 3 quotes Psalm 95 which refers to Numbers 14, which has the clear emphasis on the unbelief of the people leading to their judgment of being barred from the reward of rest in the Promised Land.
There may be another slight allusion as well, though. Numbers 20 tells the story of a similar rebellion, where the people complain due to lack of water. This time, though, Moses strikes a rock twice instead of speaking to it, as God commanded. And this time, instead of God speaking of the people’s unbelief, He speaks of Moses’s unbelief (20:12), which results in Moses not being allowed into the Promised Land. This takes place at the “waters of Meribah” (12:13).
So we see once again the association of unbelief with a judgment of not being allowed to enjoy the reward of rest in the Promised Land. The text of Hebrews 3 is laden with intricate connections, not just those that are overtly quoted!