12 But Achaz said, I will not ask, nor will I put the Lord to the test. 13 Then he said: “Hear now, O house of Dauid! Is it a small thing for you to provoke a fight with mortals? How then do you provoke a fight with the Lord? 14 Therefore the Lord himself will give you a sign. Look, the virgin shall be with child and bear a son, and you shall name him Emmanouel. 15 He shall eat butter and honey; before he knows or prefers evil things, he shall choose what is good. 16 For before the child knows good or bad, he defies evil to choose what is good, and the land that you fear from before the two kings will be abandoned. Source

21 She will give birth to a son and you will name him Jesus because he will save his people from their sins.” 22 This all happened so that what was spoken by the Lord through the prophet would be fulfilled: 23 “Look! The virgin will conceive and give birth to a son, and they will name him Emmanuel,” which means “God with us.” 24 When Joseph awoke from sleep he did what the angel of the Lord told him. He took his wife, 25 but did not have marital relations with her until she gave birth to a son, whom he named Jesus. Source