Passage
But how precious are thy thoughts unto me, O God! how great is the sum of them!
But how precious are thy thoughts unto me, O God! how great is the sum of them!
Psalms 139:15 My bones were not hidden from thee when I was made in secret, curiously wrought in the lower parts of the earth.
Psalms 139:16 Thine eyes did see my unformed substance, and in thy book all [my members] were written; [during many] days were they fashioned, when [as yet] there was none of them.
Psalms 139:17 But how precious are thy thoughts unto me, O God! how great is the sum of them!
Psalms 139:18 [If] I would count them, they are more in number than the sand. When I awake, I am still with thee.
Psalms 139:19 Oh that thou wouldest slay the wicked, O God! And ye men of blood, depart from me.
The verse centers on "precious", "thoughts", and "great". It is saying that the verse draws attention to "precious" and "thoughts", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 16's "Thine eyes did see my unformed substance..." into verse 18's "If I would count them they are...", so "precious" and "thoughts" 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 "precious" and "thoughts" with trust shaped by these words, not by a vague optimism outside the passage.