“The sign was a prophecy that received both immediate and later fulfillment ([Isaiah] 8:3–7). In the Old Testament … signs were ‘frequently offered by a prophet so that someone may know that God [was] fulfilling the promises he [had] made’ ([Isaiah] 37:30; 38:7; 1 Sam. 2:34; 10:7–9). … God indeed gave Ahaz the greatest sign in the universe, one that dealt with the Messiah, who would be called Immanuel” (Parry et al., Understanding Isaiah, 75).