Moses asks that the people be taught to number their days in light of God's Perptuity, Man's mortality, God's Penalty and God's Mercy.

1. God’s Perpetuity (v.1-2) 

Psalm 90:1-2“Lord, you have been our dwelling place in all generations. 2 Before the mountains were brought forth, or ever you had formed the earth and the world, from everlasting to everlasting you are God.”

2. Man’s Mortality (v. 3-6)

3 You return man to dust and say, “Return, O children of man!”[a] 4 For a thousand years in your sight are but as yesterday when it is past, or as a watch in the night.

5 You sweep them away as with a flood; they are like a dream, like grass that is renewed in the morning: 6 in the morning it flourishes and is renewed; in the evening it fades and withers.

3. God’s Penalty (v.7-11)

7For we are brought to an end by your anger; by your wrath we are dismayed.
8 You have set our iniquities before you, our secret sins in the light of your presence.

11 Who considers the power of your anger, and your wrath according to the fear of you?

4. God’s Mercy (v.12-17)

12 So teach us to number our days that we may get a heart of wisdom 17 Let the favor[d] of the Lord our God be upon us, and establish the work of our hands upon us; yes, establish the work of our hands!