Passage
O knowledge too wonderful for me! it is high, I cannot [attain] unto it.
O knowledge too wonderful for me! it is high, I cannot [attain] unto it.
Psalms 139:4 For there is not yet a word on my tongue, [but] lo, O Jehovah, thou knowest it altogether.
Psalms 139:5 Thou hast beset me behind and before, and laid thy hand upon me.
Psalms 139:6 O knowledge too wonderful for me! it is high, I cannot [attain] unto it.
Psalms 139:7 Whither shall I go from thy Spirit? and whither flee from thy presence?
Psalms 139:8 If I ascend up into the heavens thou art there; or if I make my bed in Sheol, behold, thou [art there];
The verse centers on "knowledge", "wonderful", "high", and "attain". It is saying that the verse draws attention to "knowledge" and "wonderful", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 5's "Thou hast beset me behind and before..." into verse 7's "Whither shall I go from thy Spirit...", so "knowledge" and "wonderful" belong inside that flow. 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 "knowledge" and "wonderful" with trust shaped by these words, not by a vague optimism outside the passage.