Isaiah 7:13

13. O house of David Wearied, truly, with Ahaz’s contemptuous trifling, the prophet turns from him personally, as if too far gone for further hope or notice, and addresses himself to the “house of David.” See note on Isaiah 7:2. The sign now to be given is not to be given to Ahaz individually, nor to him at all, except as he is part of the “house of David,” the royal stock extending to the Messiah, the Messianic kindred. And inferentially it is given for the consolation of all the faithful in Judah.

Weary men Poor mortals like Isaiah and his adherents.

My God also In Isaiah 7:11 the prophet had explicitly, to Ahaz, styled Jehovah “ thy God,” as a reminder of his allegiance to him; he now, as it were, retracts, and styles him exclusively “ my God.”