Albert Barnes Commentary Psalms 139

O Lord, you have searched me - The word rendered 'searched' has a primary reference to searching the earth by boring or digging, as for water or metals. See Job 28:3. Then it means to search accurately or closely.

And known me - As the result of that search, or that close investigation. You see all that is in my heart. Nothing is, or can be, concealed from you. It is with this deep consciousness that the psalm begins; and all that follows is but an expansion and application of this idea. It is of much advantage in suggesting right reflections on our own character to have this full consciousness: that God knows us altogether; that he sees all that is in our heart; and that he has been fully acquainted with our past life.

Thou knowest my downsitting ... - In the various circumstances of life, you know me. You know me in one place as well as in another. I cannot so change my position that you will not see me, and that you will not be perfectly acquainted with all that I say and all that I do. In every posture, in every movement, in every occupation, you have a full knowledge of me. I cannot go out of your sight; I cannot put myself into such a position that you will not see me.

Thou understandest my thought - Hebrew, “As to my thought.” That is, You see what my plans are; what I design to do; “what I am thinking about.” A most solemn reflection! How unwilling would bad people be—would even good people be—to have those around them always know “what they are thinking about.”

Afar off - Not when the “thought” is far off; but “you,” being far off, see us as clearly as if you were near. I cannot go to such a distance from you that you will not perfectly see all that I am thinking about.

You compass my path ... - Margin, “winnowest.” The Hebrew word—זרה zârâh—properly means “to scatter,” to cast loosely about—as the wind does dust; and then, to winnow—namely, by throwing grain, when it is thrashed, up to the wind (Isaiah 30:24; Jeremiah 4:11; Ruth 3:2).

Then it means “to winnow out;” that is, to winnow out all the chaff and leave all the grain—to save all that is valuable.

So here it means that God, as it were, “sifted” him (Amos 9:9; Luke 22:31).

When it is said that he did this in his path and his lying down, it is meant that he did it in every way; altogether; entirely.

And are acquainted with all my ways - All the paths that I tread; the whole course of my life. All that I do, in all places and at all times, is fully known to you.

For there is not a word in my tongue — All that I say; all that I have power to say; all that I am disposed at any time to say.

But lo, O Lord, you know it altogether — All that pertains to it. What is said, and what is meant. Merely to hear what is spoken does not necessarily imply a full knowledge of what is said — for it may be false, insincere, or hypocritical. God knows exactly what is said and what is meant.

Thou hast beset me behind and before - The word rendered “beset”—צור tsûr—means properly to press, to press upon, to compress. It commonly refers to the siege of a city or the pressing on of troops in war; it then comes to mean to besiege, hem in, or closely surround, so that there is no way of escape. This is the idea here: God was on every side of him, so he could not escape in any direction. He was like a garrison besieged in a city, with no means of escape. There is a transition here (not an unnatural one) from the idea of God's omniscience to that of His omnipresence, and the remarks that follow mainly refer to the latter.

And laid thine hand upon me - That is, if I try to escape in any direction, I find your hand laid upon me there. Escape is impossible.