they would outnumber the grains of sand;
The imagery of grains of sand is a common biblical metaphor for something immeasurable and vast, as seen in Genesis 22:17, where God promises Abraham descendants as numerous as the sand on the seashore. This comparison highlights the boundless nature of God's thoughts and plans, suggesting that they are beyond human comprehension and more numerous than anything we can imagine.

and when I awake,
This phrase can be understood both literally and metaphorically. Literally, it suggests the psalmist's awareness of God's presence upon waking each day. Metaphorically, it can represent spiritual awakening or enlightenment, aligning with themes of renewal and resurrection found in passages like Ephesians 5:14. It underscores the continuity of God's presence in both the conscious and subconscious states.

I am still with You.
This final phrase affirms the enduring relationship between the psalmist and God. It suggests a sense of security and constancy, reminiscent of God's promise in Deuteronomy 31:6 to never leave nor forsake His people. It also reflects the intimate relationship believers have with God through Christ, as seen in John 15:4, where Jesus speaks of abiding in Him. This assurance of God's perpetual presence provides comfort and strength to the faithful.

David has just spoken of God’s “precious thoughts” toward him (Psalm 139:17). He moves naturally to consider counting them—an admission that the exercise is impossible, yet it shows:

• God’s thoughts are real, not abstract; they exist in measurable abundance (Psalm 40:5).

• Every individual believer is the object of those thoughts (Matthew 10:29-31).

• David assumes literal accuracy: God actually does think about him more times than he could number.

Sand is the largest natural image of multitude Scripture offers (Genesis 22:17; Jeremiah 33:22). By choosing it, David testifies:

• God’s attention to us dwarfs any human calculation (Job 5:9).

• The promise of God’s covenant love is as sure as creation itself (Psalm 33:11).

• We are never lost in a crowd; the Lord’s specific thoughts toward His own are endless, fitting Jesus’ assurance that every hair is counted (Luke 12:7).

Sleep separates a person from conscious thought, yet David declares that the instant he wakes, God is already present:

• Night or day, the Lord keeps watch (Psalm 121:3-4).

• Rest is safe because God sustains life moment by moment (Psalm 3:5; Lamentations 3:22-23).

• Waking becomes a fresh testimony of mercy, a reminder that God’s lovingkindness doesn’t pause while we sleep (Psalm 4:8).

The climax is not merely that God remains with David, but that David remains with God:

• The relationship is secure, founded on God’s faithfulness, not David’s performance (Deuteronomy 31:6; Hebrews 13:5).

• God’s presence is personal and continual—He is the Shepherd who never leaves the sheep (Psalm 23:4; John 10:27-28).

• Even in an unknown future, David stands confident: the God whose thoughts are innumerable will never abandon him (Isaiah 41:10).

Psalm 139:18 celebrates the limitless number of God’s caring thoughts, using the immeasurable sand to drive the point home. David literally cannot count them, yet each new dawn proves their reality. Awakening finds him still wrapped in God’s unbroken presence, underscoring the security every believer enjoys in the faithful, ever-watching Lord.

"Let me count them--more than the sand they are many:

I have awaked--and still with thee."

With the countless mysteries of creation and providence the poet is so occupied, that they are his first waking thought; or, perhaps, as the Hebrew suggests, his dreams are continued into his early thoughts.

"Is not the vision He? tho' He be not that which He seems?

Dreams are true while they last; and do we not live in dreams?"

TENNYSON: Higher Pantheism.