Behold, thou shalt conceive. — St. Luke does not refer to the prophecy of Isaiah 7:14, but it is clear from Mary’s answer that she understood the words of the angel in the sense which St. Matthew gives to those of the prophet. What perplexed her was the reference to the conception and the birth in a prediction which made no mention of her approaching marriage. The absence of the reference is at least worth noticing, as showing that men were not necessarily led by their interpretation of the prophecy to imagine its fulfilment.
Shalt call his name JESUS. — See Note on Matthew 1:21. The revelation of the name, with all its mysterious fulness of meaning, was made, we may note, to Joseph and Mary independently.