12 There is One Lord Jesus Christ, a wondrous name, indirectly announced beforehand by the Prophets. For Esaias the Prophet says, Behold, your Saviour comes, having His own reward. Now Jesus in Hebrew is by interpretation Saviour. For the Prophetic gift, foreseeing the murderous spirit of the Jews against their Lord, veiled His name, lest from knowing it plainly beforehand they might plot against Him readily. But He was openly called Jesus not by men, but by an Angel, who came not by his own authority, but was sent by the power of God, and said to Joseph, Fear not to take unto you Mary your wife; for that which is con ceivedin her is of the Holy Ghost.
And she shall bring forth a Son, and you shall call His name Jesus. And immediately he renders the reason of this name, saying, for He shall save His people from their sins. Consider how He who was not yet born could have a people, unless He was in being before He was born. This also the Prophet says in His person, From the bowels of my mother has He made mention of My name; because the Angel foretold that He should be called Jesus. And again concerning Herod's plot again he says, And under the shadow of His hand has He hid Me.
Source: Catechetical Lectures (New Advent)