Psalm 90: Teach Us to Number Our Days

The oldest psalm in the collection, attributed to Moses. It sets a thousand years against a single night watch, and human life against grass that is renewed in the morning and withers by evening.

Then the prayer: teach us to number our days, that we may get a heart of wisdom.

Not so that we panic. Counting is what makes a limited thing valuable, and the request is for the counting to produce wisdom rather than fear.