Ask the Lord thy God to give thee a sign, in the depths beneath thee, or in the height above thee.
But Achaz said, Nay, I will not ask for a sign; I will not put the Lord to the test.
Why then, said Isaias, listen to me, you that are of David’s race. Cannot you be content with trying the patience of men? Must you try my God’s patience too? Sign you ask none, but sign the Lord will give you. Maid shall be with child, and shall bear a son*, that shall be called Emmanuel."
-Isaiah 7:10-14 (Knox Bible)
*Literally, the verse begins ‘Therefore the Lord, he will give you a sign’. ‘Maid shall be with child’; cf. Mt. 1.23. The Hebrew text, but not the Greek, would admit ‘a maid’ instead of ‘the maid’. In the Hebrew text, the word used should perhaps be translated ‘maid’ rather than ‘virgin’, since it refers rather to a time than to a state of life; but in view of the event, we cannot doubt that this prophecy looks forward to the Virgin Birth. No very successful attempt has been made to explain its relevance to contemporary happenings.