The Eastern Orthodox Church affirms Isaiah 7:14 as a messianic prophecy of the virgin birth of Christ. The Septuagint's reading (parthenos, 'virgin') is normative in Orthodox tradition and liturgical use. The patristic interpretation, rooted in figures like St. Athanasius and St. Cyril of Alexandria, understands Isaiah 7:14 as a clear prophecy of Mary's perpetual virginity. The virgin birth is not merely historical fact in Orthodox theology; it is inseparable from proper understanding of the Incarnation and deification (theosis) of humanity. Mary's virginity—before, during, and after birth—is affirmed as essential to Christology and Orthodox soteriological vision. This is a settled doctrine reflected in hymnody, theology, and veneration of the Theotokos.