Thou compassest my path and my lying down, and art acquainted with all my ways. Thou compassest my path - זרית zeritha thou dost winnow, ventilate, or sift my path; and my lying down, רבעי ribi, my lair, my bed.
And art acquainted - Thou treasurest up. This is the import of סכן sachan. Thou hast the whole number of my ways, and the steps I took in them.