Thought from Today's Old Testament Passage:
Above it stood the seraphims: each one had six wings; with twain he covered his face, and with twain he covered his feet, and with twain he did fly. And one cried unto another, and said, Holy, holy, holy, is the LORD of hosts: the whole earth is full of his glory. — Isaiah 6:2-3
Having life and motion, these glorious spirits use their powers with prudence and discretion. They use not all their wings for flight, but with twain each one covered his face, for even they cannot gaze upon the dazzling brightness of Jehovah's throne, and therefore in humble shamefacedness of awe they adore with veiled countenance! "With twain he covered his feet," or his body, or his lower parts, for the seraph remembers that even though sinless he is yet a creature, and therefore he conceals himself in token of his nothingness and unworthiness in the presence of the thrice Holy One. The middle pair of wings was used for flight, for more bashfulness and humility cannot offer complete adoration, there must be active obedience and readiness of heart for service. Thus they have four wings for adoration and two for active energy; four to conceal themselves, and two with which to occupy themselves in service; and we may learn from them that we shall serve God best when we are most deeply reverend and humbled in his presence. Veneration must be in larger proportion than vigour, adoration must exceed activity. As Mary at Jesus' feet was preferred to Martha and her much serving, so must sacred reverence take the first place, and energetic service follow in due course.
C. H. Spurgeon, The Treasury of the Bible, Vol. 3 (Grand Rapids, MI: Zondervan, 1962), p. 421.