Psalms 90:7-12

Humans only live a short time because God judges the sin in their lives (cf. Romans 6:23). God knows even our secret sins. They do not escape Him, and He judges us with physical death for our sins.

Assuming Moses did write this psalm, it is interesting that he said the normal human life span was 70 years. He lived to be 120, Aaron was 123 when he died, and Joshua died at 110. Their long lives testify to God’s faithfulness in providing long lives to the godly, as He promised under the Mosaic Covenant.

Since our lives are comparatively short we should number our days (Psalms 90:12). Moses meant we should realize how few they are and use our time wisely (cf. Ecclesiastes 12:1-7). Notice how often Moses mentioned "our days" or the equivalent in this psalm (Psalms 90:4-6; Psalms 90:9-10; Psalms 90:12; Psalms 90:14-15).

"The pivotal point of the text, I suggest, is the goal of a ’heart of wisdom’ (Psalms 90:12)." [Note: Brueggemann, p. 111. ]

A heart of wisdom refers to discernment of Yahweh’s purposes.