Psalms 78:42 Commentary: Forgetfulness and Rebellion

Psalm 78 is a historical psalm, a teaching song that traces Israel's story from the Exodus to the Davidic monarchy. Its purpose, as Calvin observed, is to show 'how God adopted for himself a Church from the posterity of Abraham, how tenderly and graciously he cherished it, how wonderfully he brought it out of Egypt', and then to expose 'how perversely and treacherously' Israel revolted. Verse 42 sits at a turning point. The preceding verses (38, 41) describe God's mercy even in the wilderness: he forgave, turned away his anger, remembered they were flesh. But the people 'turned again and tempted God.' Verse 42 is the diagnosis of why.

The 'hand' here is a shorthand for the entire Exodus deliverance, the plagues, the crossing of the sea, the destruction of Egypt's army. The 'day' is the Passover night, the fixed moment of redemption that every Israelite generation was commanded to remember (Exodus 13:9). The 'adversary' is Pharaoh and his forces, though Barnes notes the Hebrew word tzar can also mean 'affliction', a double meaning that would not change the essential point. The poet is pressing this: God's past acts should have anchored trust. Instead, the people's memory failed them, and that failure opened the door to every subsequent sin.

This forgetfulness is not a blank in their minds; it is a willful neglect. As Gill says, 'times when as well as places where deliverances and salvation have been wrought should not be forgotten; and forgetfulness of the goodness of God in times past is often the cause and occasion of sinning.' The verse thus stands as a hinge between God's relentless mercy and Israel's relentless rebellion.

The supplied commentaries mention no significant textual variants for this verse. The only lexical note is the margin in the Hebrew tradition (noted by Barnes) that the word translated 'adversary' (tzar) can also be read as 'affliction,' but this is a semantic range, not a manuscript variation.

Psalm 78 as a whole has been used from early Jewish liturgy to the present as a teaching tool for remembering God's acts. The Targum (cited by Gill) already paraphrases 'his hand' as 'the miracles of his hand,' showing an early interpretive tradition that emphasizes the wonders. In the Christian tradition, the psalm has been read both as a warning against ingratitude and as a foreshadowing of Christ, the ultimate Redeemer. The verse is often connected to the sacrament of remembrance in Christian worship, echoing the Exodus mandate to recount God's deliverance. Its theme of forgetfulness as the seed of rebellion has been a staple in homiletical literature, from the Church Fathers to Reformation sermons, always calling hearers to 'remember his marvelous works.'

Three-point outline

1. What they forgot: God's hand, not just abstract power, but the concrete, muscular rescue from Egypt (Barnes: 'manifestations of his power').
2. When they forgot: the day, a specific, non-negotiable moment (the Exodus) that should have been seared into memory.
3. The result: rebellion. Forgetting leads to distrust; distrust leads to sin (Psalm 78:22: 'because they didn’t believe in God').

Five-point outline

1. God’s mercy in the wilderness (vv. 38, 39), he held back his anger.
2. Israel’s ongoing rebellion (vv. 40, 41), they kept testing him.
3. The root cause diagnosed (v. 42), forgetfulness of the Exodus.
4. The Exodus recalled in detail (vv. 43, 51), plagues and signs in Egypt.
5. God’s shepherding despite failure (vv. 52, 55), he still led them through the wilderness.

Illustration hooks

• Forgetting a wedding anniversary: the date itself is not magical, but the failure to remember the day you promised everything signals a deeper drift.
• A firefighter who rescued a family from a burning house: ten years later, when that family faces a new crisis, did they forget whose hands pulled them out? That forgetfulness would change how they ask for help.
• Every generation has a defining rescue, a war, a recovery, a providential provision. When the children of that generation stop telling the story, they drift into self-reliance.

Questions your congregation is asking

• How do I keep God’s past faithfulness from fading into background noise?
• Is it possible to believe in God but still functionally forget what he has done?
• Why do we so easily lose gratitude and slip into complaining?

Psalm 78:42 sits at the center of Israel's long history of rebellion. It isolates one cause: they stopped remembering God's concrete act of rescue. In your group, walk through what 'remembering' actually looks like, in ancient Israel and in your own life.

Discussion questions

1. What specific events does the psalmist recall when he mentions God's 'hand'? Scan verses 43, 51 for the details.
2. How does the idea of 'day' in this verse connect to the Old Testament command to remember the Exodus (Exodus 13:9)? Why is a specific date important?
3. Barnes notes the Hebrew word for 'adversary' can also mean 'affliction.' How might that double meaning deepen our understanding of what God saved them from?
4. Psalm 78:11 says 'They forgot his doings, his wondrous deeds.' How does forgetting a past act of God lead to distrust in a present crisis?
5. Read Judges 8:34, 'The children of Israel didn’t remember Yahweh their God.' This pattern repeats across generations. What keeps us from passing down the story of God's rescue to the next generation?
6. Where in your own life have you functionally 'forgotten' a deliverance God worked for you? Not a mental blank, but a failure to let it shape your daily trust?
7. This passage ends with God still leading his people like sheep (v. 52). How does the psalm hold together both Israel's failure and God's persistent kindness?