12. a sign--"the sign."
      the babe--"a Babe."
      a manger--"the manger." The sign was to consist, it seems, solely in the overpowering contrast between the things just said of Him and the lowly condition in which they would find Him--Him whose goings forth have been from of old, from everlasting, "ye shall find a Babe"; whom the heaven of heavens cannot contain, "wrapt in swaddling bands"; the "Saviour, Christ the Lord," lying in a manger! Thus early were these amazing contrasts, which are His chosen style, held forth. (See 2Co 8:9.)

JFB.