8 “If I go up,” says he, “to heaven, You are there: if I go down to Hades, You are present”. At length, miserable runaway, you have learned, that by no means can you make yourself far from Him, from whom you have wished to remove far away. Behold, He is everywhere; thou, whither will you go? He has found counsel, and that inspired by Him, who now deigns to recall him....If by sinning I go down to the depths of wickednesses, and spurn to confess, saying, “Who sees me” (for “in Hades who shall confess to You?”) there also You are present, to punish.
Whither then shall I go that I may flee from Your presence, that is, not find You angry? This plan he found: So will I flee, says he, from Your Face, so will I flee from Your Spirit; from Your avenging Spirit, Your avenging Face thus will I flee. How? “If I take again my wings right forward, and abide in the utmost parts of the sea”. So can I flee from Your Face. If he will flee to the utmost part of the sea from the Face of God, will not He from whom he flees be there?...For what are “the utmost parts of the sea,” but the end of the world?
Thither let us now flee in hope and longing, with the wings of twofold love; let us have no rest, save in “the utmost parts of the sea.” For if elsewhere we wish for rest, we shall be hurled headlong into the sea. Let us fly even to the ends of the sea, let us bear ourselves aloft on the wings of twofold love; meanwhile let us flee to God in hope, and in faithful hope let us meditate on that “end of the sea.”
Source: The Enarrations, or Expositions, on the Psalms (New Advent)