1....“Bless the Lord, O my soul.” Let the soul of us all, made one in Christ, say this. “O Lord my God, You are magnified exceedingly!”. Where are You magnified? “Confession and beauty You have put on.” Confess ye, that you may be beautified, that He may put you on. “Clothed with light as a garment”. Clothed with His Church, because she is made “light” in Him, who before was darkness in herself, as the apostle says: “You were sometime darkness, but now light in the Lord.” “Stretching out the heaven like a skin:” either as easily as thou dost a skin, if it be “as easily,” so that you may take it after the letter; or let us understand the authority of the Scriptures, spread out over the whole world, under the name of a skin; because mortality is signified in a skin, but all the authority of the Divine Scriptures was dispensed unto us through mortal men, whose fame is still spreading abroad now they are dead.
Source: The Enarrations, or Expositions, on the Psalms (New Advent)