Psalm 90 is likely the oldest psalm of the collection. It’s a prayer of Moses asking God to have mercy on “frail human beings living in a sin-cursed universe” (The MacArthur Study Bible). As the author focuses on man’s brevity of life, he asks God to “teach us to number our days that we might get a heart of wisdom” (Psalm 90:12).Reading the passage, I decided to take it liter...