The Sign Achaz Would Not Ask: A Virgin Shall Conceive
Old Testament: Isaias 7:10-14
And the Lord spoke again to Achaz, saying: Ask thee a sign of the Lord thy God either unto the depth of hell, or unto the height above. And Achaz said: I will not ask, and I will not tempt the Lord. And he said: Hear ye therefore, O house of David: Is it a small thing for you to be grievous to men, that you are grievous to my God also? Therefore the Lord himself shall give you a sign. Behold a virgin shall conceive, and bear a son, and his name shall be called Emmanuel.
Old Testament, also: Deuteronomy 6:16
Thou shalt not tempt the Lord thy God, as thou temptedst him in the place of temptation.
New Testament: Matthew 1:22-23; Matthew 4:7; Luke 1:34, 38
Now all this was done that it might be fulfilled which the Lord spoke by the prophet, saying: Behold a virgin shall be with child, and bring forth a son, and they shall call his name Emmanuel, which being interpreted is, God with us. ... Jesus said to him: It is written again: Thou shalt not tempt the Lord thy God. ... And Mary said to the angel: How shall this be done, because I know not man? ... And Mary said: Behold the handmaid of the Lord; be it done to me according to thy word.
The connection
King Achaz was afraid of two kings marching on Jerusalem, and God offered him any sign he liked, "either unto the depth of hell, or unto the height above" (Isaias 7:11). Achaz refused in the words of the Law: "I will not ask, and I will not tempt the Lord" (7:12). The Law says, "Thou shalt not tempt the Lord thy God, as thou temptedst him in the place of temptation" (Deuteronomy 6:16), and that place was Massa, where Israel demanded proof: "Is the Lord amongst us or not?" (Exodus 17:7). To tempt God is to demand a sign He has not offered. Achaz turned the commandment round to refuse a sign God was offering, for he had already decided to trust in the king of Assyria (4 Kings 16:7). The sign came anyway, to "the house of David": "Behold a virgin shall conceive, and bear a son, and his name shall be called Emmanuel" (Isaias 7:14). St Matthew says this was fulfilled when Mary conceived by the Holy Ghost, and gives the meaning of the name, "God with us" (Matthew 1:22-23). Christ Himself used Achaz's verse truly. When the devil told Him to throw Himself from the Temple, He answered, "It is written again: Thou shalt not tempt the Lord thy God" (Matthew 4:7). Achaz refused the sign God offered; Christ refused the sign the devil demanded. And a daughter of David's house answered as Achaz would not. Told what God would do, Mary asked, not in doubt but to understand, "How shall this be done, because I know not man?", and then consented: "be it done to me according to thy word" (Luke 1:34, 38). St Irenaeus reads the depth and the height as Christ's own road: the Lord gave "a sign, in the depth below, and in the height above, which man did not ask for, because he never expected that a virgin could conceive". The Catechism sees the promise through Isaias fulfilled in the virginal conception (CCC 497).
Moral sense
Scripture shows four ways of meeting a sign. Some demand one God has not given: "An evil and adulterous generation seeketh a sign" (Matthew 12:39). Some refuse the one He gives and call it reverence, as Achaz did. Some doubt it when it comes: "Whereby shall I know this?" said Zachary, and was struck dumb (Luke 1:18). Mary asked how, believed, and said yes. The soul is to do as she did, neither demanding proof nor hiding from God behind pious words, but asking in faith and then giving itself: "Behold the handmaid of the Lord."
Anagogical sense
Whether men refuse a sign or demand one, God gives His own, and it is always His Son. To Achaz's house He gave the Virgin with child; to the generation that demanded signs He gave "the sign of Jonas the prophet" (Matthew 12:39), the Son of man three days in the heart of the earth. A birth and a resurrection. The name is the promise: Emmanuel, "God with us", opens St Matthew's Gospel, and the same Gospel closes with Christ's last word, "behold I am with you all days, even to the consummation of the world" (Matthew 28:20).
The Fathers
St Justin Martyr, First Apology 33: "This, then, 'Behold, a virgin shall conceive,' signifies that a virgin should conceive without intercourse. For if she had had intercourse with any one whatever, she was no longer a virgin". St Irenaeus, Against Heresies III.19.3: "Wherefore also the Lord Himself gave us a sign, in the depth below, and in the height above, which man did not ask for, because he never expected that a virgin could conceive, or that it was possible that one remaining a virgin could bring forth a son". St Jerome, in the Catena on Matthew 1:22-23: "I do not think I ever met with Halma used of a married woman, but of her that is a virgin".
Warrant
Scriptural, because St Matthew names the fulfilment and quotes the prophet (Matthew 1:22-23). St Justin (First Apology 33) and St Irenaeus (Against Heresies III.19.3) read the sign of the Virgin, and St Jerome discusses the Hebrew. Checked in the languages. The Septuagint of Isaias 7:12 has ou me peiraso Kyrion, I will not tempt the Lord, the verb of Deuteronomy 6:16 (ouk ekpeiraseis Kyrion) that Christ quotes at Matthew 4:7. The Hebrew of 7:14 has almah, a young unmarried woman, as St Jerome says, adding: "I do not think I ever met with Halma used of a married woman, but of her that is a virgin". The Septuagint renders it parthenos, as it renders the almah Rebecca at Genesis 24:43, whom 24:16 calls a virgin not known to man. The link between Achaz's words and Deuteronomy 6:16, Christ's use of the same verse, and the four ways of meeting a sign were Dunk's observations; no Father in the site's corpora was found making them. The lead itself came from research Dunk asked for to fill the gaps in the site's chronology.
Catechism of the Catholic Church, paragraph 497.
The verses
Isaias 7:10 · Isaias 7:11 · Isaias 7:12 · Isaias 7:13 · Isaias 7:14 · Deuteronomy 6:16 · Matthew 1:22 · Matthew 1:23 · Matthew 4:7 · Luke 1:34 · Luke 1:38
