Psalm 90: Teach Us to Number Our Days

The placement of this psalm is itself a sermon. Psalm 89 has just ended in stunned grief: the Davidic covenant looks broken, the throne is in the dust, the enemy has triumphed. The reader who turns the page expects another lament. Instead the editors of the Psalter reach back over a thousand years and pull out a prayer of Moses, the man who led Israel before there was ever a king. Book IV opens not with David but with Moses, and the implicit message is enormous: when the throne fails, when the institutions you trusted collapse, the people of God are not orphaned. The God who carried Israel through forty years in the wilderness, before there was a temple or a king or a city, is still our dwelling place. Verse 1 sets the key for the entire book: "Lord, you have been our dwelling place in all generations." Not the palace. Not the temple. The Lord himself.

The Mosaic ascription is debated. Many scholars note linguistic features that suggest a later hand, and the cleanest reading is that this psalm preserves a Mosaic tradition that was set down in writing later, the way the Pentateuch itself reached its final form over time. Either way, the voice is unmistakably wilderness. Verse 3 says, "You return man to dust," and any Israelite who knew the Numbers 14 story would feel the weight: a whole generation, six hundred thousand fighting men, died in the sand because they had refused to trust God at Kadesh. Moses, who led their funerals year after year, knew what it was to count graves. When verse 10 says "our days are seventy years, or eighty if we have the strength," this is not a sentimental observation; it is the math of a man who had buried tens of thousands of his own kinsmen.

The Hebrew word for "dwelling place" in verse 1 is "ma'on," a word also used for an animal's lair, a habitation, a refuge. It carries the warmth of a place a creature returns to instinctively. Moses is not saying God is a doctrine; he is saying God is the place we crawl into. Verses 5 and 6 then pile up the brevity of human life with painful imagery: we are swept away like a flood, we are like grass that springs up in the morning and is dry by evening. Anyone who has lived in a wadi country knows this picture. A winter storm fills the desert with green; two weeks later the sun has burned it brown. The people watching this psalm be sung in the wilderness camp could see the very grass the words described. They knew exactly how long it lasted.

Verse 12 is the wisdom climax of the prayer: "Teach us to number our days, that we may gain a heart of wisdom." The Hebrew for "number" is "manah," the same root used for counting out shekels or measuring grain. Moses is asking God for a kind of arithmetic of mortality, a daily reckoning that makes us wise. Notice he does not ask God to lengthen the days; he asks God to teach the heart to count them. The psalm closes with one of the most under-quoted petitions in the Bible: "Establish the work of our hands." Twice in verse 17. Moses, who watched a whole generation's labor fall into graves, asks God to make the work of the next generation last. This is the prayer of a leader who has seen too much fail and still believes that if God establishes it, it will stand.