Psalm 139 is about the omniscience of God, that is, the fact that God is all-knowing and all-seeing. But it applies this fact not just in a ‘spooky God-is-onto-you’ way but as a comfort for God’s people. The theme of ‘God watching over his people’ is a common one in the psalms and indicates God’s love and care for his people. It stands alongside the shepherding metaphor also common in the psalms. But this psalm takes that theme to a new level. It speaks about God’s knowledge of our thoughts and even the fact that God predestines the path of our lives. It celebrates the fact that God loves us so much we could not get away from him even if we tried. In the last part of the psalm, not included in our adaptation of this psalm, the mood turns to the condemnation of evil. And this is quite a natural movement even if it somewhat distasteful to those who prefer the sweeter sentiment of the first half of the psalm. The idea of God watching people goes two ways, and this also is common in the psalms. For God’s people it entails safely and care but for those who set themselves against God it entails judgement. In this context the omniscience of God means that God sees their evil and will store up judgement for them unless they turn and repent. Hence naturally again the psalm ends with a cry to God to examine our hearts to see if there is any evil in us that we might be delivered from it.