For thou hast {h} possessed my reins: thou hast covered me in my mother's womb.

(h) You have made me in all parts and therefore must know me.

Matthew Henry's Concise Commentary

139:7-16 We cannot see God, but he can see us. The psalmist did not desire to go from the Lord. Whither can I go? In the most distant corners of the world, in heaven, or in hell, I cannot go out of thy reach. No veil can hide us from God; not the thickest darkness. No disguise can save any person or action from being seen in the true light by him. Secret haunts of sin are as open before God as the most open villanies. On the other hand, the believer cannot be removed from the supporting, comforting presence of his Almighty Friend. Should the persecutor take his life, his soul will the sooner ascend to heaven. The grave cannot separate his body from the love of his Saviour, who will raise it a glorious body. No outward circumstances can separate him from his Lord. While in the path of duty, he may be happy in any situation, by the exercise of faith, hope, and prayer.