A symbolic name in Hebrew, written in Isaiah 7:14 and 8:8, which means “God is with us” or “May God be with us.” It is frequently spelled Emmanuel. Because of its use in Matthew 1:8 the name has become a title for Jesus.
Originally in the Old Testament context, Isaiah asked King Achaz, during a political battle in 735-733 BC, to place his trust in the God Yahweh rather than the Assyrian alliances. Even though a sugn of divine power was shown to Achaz he refused to trust Yahweh. (Isaiah 7:11-12) Then Isaiah predicts a complex sign of deliverance and future suffering.
Part of the sign was the birth of a child from a young woman, and this child was to be named Immanuel. Many authorities interpeted the child in this prediction to have been Achaz’s son Hexekiah, through whom the Davidic dynasty was to be continued.
Later believers thought that the solemnity of Isaiah’s prediction led many to seriously believe the above, but these believers came to think the Isaiah prediction referred to the birth of the Messiah who would fulfill the hopes of the Davidic kingdom and establish God’s pressence among humankind. Matthew saw the birth of Jesus as fulfilling this prophesy.
The word used referring to the mother of the child was exchanged. In Isaiah 7:14 the Hebrew word almah was used which technically means “young woman.” However, the Septuagint, which was written in Greek, uses the word parthenos which means “virgin.” Matthew chosed the Greek word when describing the virgin birth of Jesus. (See: The Goddess, The Virgin and The Mother) A.G.H.
Source: (Immanuel, Robert J.Hennessey, O.P., Albertus Magnus College, New Haven, CT) 61.