O LORD, you have searched me (thoroughly) and have known me.
You know my downsitting and my uprising; You understand my thought afar off.
You sift and search out my path and my lying down, and are acquainted with all my ways.
For there is not a word in my tongue [still] unuttered, but lo, O Lord, You know it altogether.
You have beset me and shut me in behind and before, and have laid Your hand upon me.
Your (infinite) knowledge is too wonderful for me; it is high above me, I cannot reach it.
Where could I go from Your Spirit? Or where could I flee from Your presence?
If I ascend up into Heaven, You are there; if I make my bed in Sheol [the place of the dead], behold, You are there.
If I take the wings of the morning and dwell in the uttermost parts of the sea,
Even there shall Your hand lead me, and Your right hand shall hold me.
If I say, Surely the darkness shall cover me, and the night shall be the only light about me,
Even the darkness hides nothing from You, but the night shines as the day; the darkness and the light are both alike to You. [Psalm 139:1-12]. [Amplified Bible].
The various components of this psalm expose us to the intensely personal relationship between the psalmist and his God.
I. The Lord's Discernment of Individuals (139:1-6)
1-6 The Lord "knows" his own-a word that means complete divine discernment. In his prayer (vv. 23-24), the psalmist prayed for the Lord to examine him as in a judicial case and to declare him to be innocent of all charges. Now that the ordeal is over and he has been justified by the Lord, the psalmist testifies that the Lord is a righteous judge. The Lord knows him through and through.
The accused is not afraid of his judge, for the Judge is more than an arbiter; he is the one in whom the psalmist has found protection. The knowledge of God referred to here is a knowledge that graciously discerns in favor of those who are loyal to the Lord. By grace humans are blessed. The psalmist exclaims that God's favorable acts toward him are "too wonderful" and "too lofty" to apprehend.
II. The Lord's Perception of Individuals (139:7-12)
7-12 The "presence" (parallel with "Spirit") of God is everywhere; hence he perceives all things in all places. We cannot hide from the all-seeing eye of the Lord. Unlike pagan deities, the Lord's authority extends to "the heavens . . . the depths . . . the wings of the dawn . . . the sea." The Lord's hand protects his children wherever they are, even in "darkness." There is only light with God, and his light brightens up the darkness so that the psalmist can say affirmatively, "The night will shine like the day, for darkness is as light to you" (v.12).
[NIV BIBLE COMMENTARY Volume I: Old Testament].
JESUS IS LORD.