Perhaps this unique and mystical feast of the Virgin Mary might be a portal through which Muslims might come to know Jesus Christ through the Holy Spirit. Because Muslims venerate Mary (Miriam), and retain awareness of the virgin birth of Jesus (Isa), they might be intrigued and drawn to learn the truth about Jesus and His Most Pure Mother, specifically, why the Virgin Birth is a sign of the divinity of Christ, as Isaiah says:
Therefore the Lord himself shall give you a sign; Behold, a virgin shall conceive, and bear a son, and shall call his name Immanuel. (Isaiah 7:14)
As the Evangelist Matthew tells us in his gospel (1:23), Immanuel means "God with us," and the meaning is clear. God becomes incarnate, taking on human nature, in the person of Jesus.
Regarding the Feast of the Entrance of the Virgin Mary, the Mother of God, into the Temple, this excerpt from an article by a monk at St Tikhon's Monastery (published in the book, These Truths We Hold) conveys some of the depth and fulfillment contained therein:
The Entrance of the Theotokos into the Temple (Nov. 21)
Soon after the beginning of the Nativity Fast (Advent), the Holy Church celebrates the Feast of the Entrance of the Most-Holy Theotokos [Birthgiver of God] into the Temple. Here we encounter the holiness of Mary a small child separated from the world, brought to live in the Temple a life set apart, consecrated, and in a state of intimacy with God something that all of us are called to be.
We also see in this Feast a comparison between the Temple of stone and Mary, the Living Temple, the Temple of the Savior. For she will bear God the Word, the God-Man, in her womb, thus showing herself to be a holier Temple than that at Jerusalem. It is the Living Temple, the instrument of the Incarnation, which sanctifies the Temple built of stone...
A deep mystery covers the earthly life of the Most-Holy Theotokos from her childhood to her repose. Her life in the Jerusalem Temple was concealed. If you were to ask me, said the Blessed Jerome, how the Most-Holy Virgin passed the time of her youth, I would answer that this is known only to God Himself and the Archangel Gabriel detailed to protect her.
In Church Tradition, however, is preserved information that during her sojourn in the Jerusalem Temple, the Most-Pure Virgin was educated in the community of pious virgins, diligently reading Holy Scriptures, occupied with handiworks, perpetually in prayer and growing up with love towards God.
In remembrance of the Entry into the Temple of the Most-Holy Theotokos, the Church, from ancient times, instituted a solemn Feast. Information concerning the celebration of the Feast in the first centuries of Christianity is found in the tradition of Palestinian Christians, which says that when the Holy Queen Helena came to Palestine, she erected a church in honor of the Entrance into the Temple of the Most-Holy Theotokos. Thus the Feast of the Entrance into the Temple of the Most-Holy Theotokos, pre-announcing the Incarnation of God on earth, proclaims salvation to all Christians.
Troparion of the Feast (Tone 4)
Today is the prelude of the good will of God, of the preaching of the salvation of mankind. The Virgin appears in the Temple of Cod, in anticipation proclaiming Christ to all. Let us rejoice and sing to her: Rejoice, O divine Fulfillment of the Creator's dispensation!
Kontakion of the Feast (Tone 4)
The most pure Temple of the Savior; the precious Chamber and Virgin; the sacred Treasure of the glory of God, is presented today to the house of the Lord. She brings with her the grace of the Spirit, which the angels of God do praise. Truly this woman is the Abode of Heaven!
For many more resources into this wondrous and profound Feast, go here...