Charles H. Spurgeon on Psalms 139:3

Thou compassest my path and my lying down. My path and my pallet, my running and my resting, are alike within the circle of thine observation. Thou dost surround me even as the air continually surrounds all creatures that live. I am shut up within the wall of thy being; I am encircled within the bounds of thy knowledge. Waking or sleeping I am still observed of thee. I may leave thy path, but you never leave mine. I may sleep and forget thee, but thou dost never slumber, nor fall into oblivion concerning thy creature. The original signifies not only surrounding, but winnowing and sifting. The Lord judges our active life and our quiet life; he discriminates our action and our repose, and marks that in them which is good and also that which is evil. There is chaff in all our wheat, and the Lord divides them with unerring precision. And art acquainted with all my ways. Thou art familiar with all I do; nothing is concealed from thee, nor surprising to thee, nor misunderstood by thee. Our paths may be habitual or accidental, open or secret, but with them all the Most Holy One is well acquainted. This should fill us with awe, so that we sin not; with courage, so that we fear not; with delight, so that we mourn not.