Teach us to number our days that we may get a heart of wisdom. (Ps. 90: 12)
This verse is often treated as if it were a proverb that means, “Life is short, so live wisely.” But in the context of the whole psalm, it means much more than that, as we will see. It is a key part of a meditation on God and on living as the people of God.
In Hebrew, verse 12 begins with the words “to number our days.” This phrase picks up the theme of time that is so pervasive in this psalm. A reflection on time leads us to see how weak we are and how short our lives are: “You return man to dust and say, ‘Return, O children of man!’ . . . You sweep them away as with a flood; they are like a dream, like grass that is renewed in the morning: in the morning it flourishes and is renewed; in the evening it fades and withers... The years of our life are seventy, or even by reason of strength eighty; yet their span is but toil and trouble; they are soon gone, and we fly away” (vv. 3, 5–6, 10). Here, Psalm 90 shows its connection to the concerns of Psalm 89 about man’s frailty: “Remember how short my time is! For what vanity you have created all the children of man! What man can live and never see death? Who can deliver his soul from the power of Sheol?” (Ps. 89:47–48). Such realism about our weakness is the necessary foundation of any true wisdom. “O Lord, make me know my end and what is the measure of my days; let me know how fleeting I am” (Ps. 39:4).
The shortness and weakness of human life are the fruit of sin and judgment in the world. The psalmist acknowledges that sin frankly, saying, “You have set our iniquities before you, our secret sins in the light of your presence” (Ps. 90:8). He knows that his holy God visits His judgment on sinners. “For all our days pass away under your wrath; we bring our years to an end like a sigh. . . . Who considers the power of your anger, and your wrath according to the fear of you?” (vv. 9, 11). It is surely frightening to think that God’s wrath will equal all the obedience that is due to Him.
Although life is short and the wrath of God terrifying, the mercy and protection of God for His people are great. God is the home of His people: “Lord, you have been our dwelling place in all generations” (v. 1). Through all the generations of His people’s existence, reaching back all the way to creation, God has always preserved and protected His people. Even in the garden of Eden, He promised that He would redeem His own (Gen. 3:15). God remains the home of His people because He is the redeeming God.
Moses reminds us that while the life of man is frail and short, God is eternal. “Before the mountains were brought forth or ever you had formed the earth and the world, from everlasting to everlasting you are God” (v. 2). Moses takes us back before God created the earth to remind us that our God is before and beyond time and this world. He has always been, and He is sufficient to Himself without us. Moses makes this point in another way in verse 4: “For a thousand years in your sight are but as yesterday when it is past, or as a watch in the night.” Time does not have the same meaning for God that it has for us. For us, a thousand years is a time so long that we cannot really imagine experiencing it. For God, it is no different from a very short period of time. He is eternal, above the time that He created.
This eternal God directs the course of history by His infinite power. Moses, who had seen the power of God often displayed in the deliverance of Israel from Egypt, continues to pray that the majesty of God’s works would remain before the eyes of the people: “Let your work be shown to your servants, and your glorious power to their children” (v. 16). As God had brought suffering by His power, so Moses prays that God will send blessing: “Make us glad for as many days as you have afflicted us, and for as many years as we have seen evil” (v. 15). If our need is to number our days by contrasting their shortness with the eternal nature of God, then our prayer to God is that He would teach us: “Teach us to number our days.” We will never learn that lesson in our own strength. We are not only ignorant if left to ourselves, but we suppress the truth in unrighteousness (Rom 1:18). We convince ourselves that we have a long time to live, and as long as we are healthy, we really believe that we will live forever in this body. We need a teacher, and the only teacher who can rescue us from ourselves is God.