I read Psalm 139 last night and again this morning. A few thoughts...
As with the Psalm that I quoted yesterday, David here affirms that God's thoughts are infinitely above his own. In this case, God's thoughts seem to be directed right at me. After saying that God knows our thoughts, our words, our motions and our hearts utterly and completely, David remarks, "Such knowledge is too wonderful for me, too lofty for me to attain."
The Psalm goes on with the portion that is probably the best known -- "Where can I go from your Spirit? Where can I flee from your presence? ... For you created my inmost being; you knit me together in my mother's womb. I praise you because I am fearfully and wonderfully made; your works are wonderful, I know that full well."
Then, again, David worships God for his incomprehensible majesty, "How precious to me are your thoughts, O God! How vast is the sum of them!"
The well-known end of the Psalm particularly made me sit up and think: "Search me, O God, and know my heart; test me and know my anxious thoughts. See if there is any offensive way in me, and lead me in the way everlasting."
In light of God's exhaustive wisdom and knowledge, David seems to be specifically inviting God to search and test his anxious thoughts (excuse me if I'm making a weak exegetical point because I haven't checked the Hebrew; that's just what NIV and NASB say). Those anxious thoughts seem to be creating the potential for there to be an "offensive way in me." I'm not typically an anxious person, but I've been having more anxious thoughts than usual lately. And those anxious thoughts are offensive to God; instead of harboring them, I am to cast my cares upon the Lord, because he cares for me (1 Peter 5:7, cf. Phil 4:6-7). So my prayer today is that God -- who already knows me more thoroughly than I know myself -- will help me to cast my anxious thoughts upon him and to rest in his sovereign grace.