Jehovah wanted Ahaz to ask for a sign (7:10-25). This sign is related to the ushering in of Christ, who was born of a virgin.
Ahaz said that he would not ask and would not try Jehovah (v. 12). Isaiah considered this as exhausting the patience of his God (v. 13).
Verse 14 says, "Therefore the Lord Himself will give you a sign: Behold, the virgin will conceive and will bear a son, and she will call his name Immanuel." Immanuel means "God with us." This word concerning a virgin bearing a son is quoted in Matthew 1:23 and applied to the Lord Jesus.
The actual fulfillment of this sign was the birth of a son by Isaiah's wife (8:3). The son was named Maher-shalal-hash-baz, which means "Swift is the booty, hastening is the prey." This name indicates the carrying away of the wealth of Damascus and the spoil of Samaria before the king of Assyria (8:4).
Until the child knew how to refuse evil and choose good, he would eat curds and honey. This indicates that the land of the two kings whom Ahaz dreaded would be abandoned, made desolate, by the king of Assyria (7:15-16).
Isaiah 7:17-25 and 8:5-8 speak of the invasion of the army of the king of Assyria. Thus far, we have four parties: the party of Aram, the party of the northern kingdom of Israel, the party of the southern kingdom of Judah, whose king was Ahaz, and the party from Assyria. God sent the army from Assyria in the northeast to deal with the king of Aram and the king of Israel, who were threatening Ahaz.