Passage
To him that excelleth. A Psalme of David. O Lord, thou hast tried me and knowen me.
To him that excelleth. A Psalme of David. O Lord, thou hast tried me and knowen me.
Psalms 139:1 To him that excelleth. A Psalme of David. O Lord, thou hast tried me and knowen me.
Psalms 139:2 Thou knowest my sitting and my rising: thou vnderstandest my thought afarre off.
Psalms 139:3 Thou compassest my pathes, and my lying downe, and art accustomed to all my wayes.
The verse centers on "excelleth", "psalme", "david", "lord", "thou", "hast", "tried", and "knowen". It is saying that the verse draws attention to "excelleth" and "psalme", so its meaning should be read from those terms before moving to application.
The next verse adds "Thou knowest my sitting and my rising...", so "excelleth" and "psalme" should be read forward into that movement. In Psalms context, the local focus is worship, trust, the LORD's kingship, and covenant mercy.
A plain takeaway is to answer the verse's own emphasis on "excelleth" and "psalme" with trust shaped by these words, not by a vague optimism outside the passage.