Life in perspective; all is vanity.
v1-3: Guarding the lips, Ps 139.4; 141.3, particularly in the presence of the wicked, Ps 38.13-14. Sometimes silence is the way of wisdom. In this situation, David remained silent for a period, and finally felt compelled to speak
v4-6: Life is transitory, quickly passing. We need to know this truth; look to the Lord to teach us. All our labours must reflect this reality. For us, life seems long; but that is a false understanding.
v7-8: Through it all our only hope is in God, Ps 38.15. We need to blessing in this life, and therefore we pray for God's deliverance and blessing. See Ps 62.5; 87.7. Do we think we can live without Him? Do we think our lives are our own?
v9-10: The psalmist has suffered a divine rebuke for his wrong doing, as in Ps 38.11,13.
v11: The experience of one is true, in principle, for others too. God does deal with His people.
v12-13: In this difficult time, the psalmist looks to the Lord, depending on Him.