If we consider the moment, chosen by Isaiah for announcing the Messiah and adding his seal to the national belief in the advent of a glorious Son of David, we find some significance in the fact that it was a moment, when the throne of David was unworthily filled and David's dynasty was for the first time seriously threatened. It is impossible to dissociate the birth of a boy called _Immanuel_, and afterwards so closely identified with the fortunes of the whole land (vii. 8), from the public expectation of a King of glory; and critics are almost unanimous in recognizing Immanuel again in the Prince-of-the-Four-Names in chap. ix. Immanuel, therefore, is the Messiah, the promised King of Israel. But Isaiah makes his own first intimation of Him, not when the throne was worthily filled by an Uzziah or a Jotham, but when a fool and traitor to God abused its power, and the foreign conspiracy to set up a Syrian prince in Jerusalem imperilled the whole dynasty. Perhaps we ought not to overlook the fact, that Isaiah does not here designate Immanuel as a descendant of David. The vagueness with which the mother is described has given rise to a vast amount of speculation as to what particular person the prophet meant by her. But may not Isaiah's vagueness be the only intention he had in mentioning a mother at all? The whole house of David shared at that moment the sin of the king (vii. 13); and it is not presuming too much upon the freedom of our prophet to suppose, that he shook himself loose from the tradition, which entailed the Messiah upon the royal family of Judah, and at least left it an open question, whether Immanuel might not, in consequence of their sin, spring from some other stock. It is, however, far less with the origin, than with the experience, of Immanuel that Isaiah is concerned; and those who embark upon curious inquiries, as to who exactly the mother might be, are busying themselves with what the prophet had no interest in, while neglecting that in which really lay the significance of the sign that he offered.