The Entry into the Temple of the Most-holy Virgin Mary.
When the Virgin Mary reached the age of three years, Her pious parents prepared to fulfill their promise. They called together their relatives, invited friends the same age as their daughter, dressed Her in Her finest clothes, and accompanied by the people singing hymns, they brought Her to the Temple in Jerusalem to be consecrated to God. Her friends and Mary Herself walked with burning candles in their hands. Led by the chief priest, the priests, while singing hymns, came out of the Temple to meet them.
Joachim and Anna with reverent prayers set Mary on the first step of the flight of stairs leading to the Temple. This staircase had fifteen high steps, according to the number of the psalms which the priests chanted upon entering the Temple.
There, three-year-old Mary Herself climbed the high steps without any assistance. At the top, the chief priest met and blessed Her as he always did with all who came to be consecrated to God. Then, by the inspiration of the Holy Spirit, he led Her into the Holy of Holies. This was the most sacred place in the Temple. No one had the right to enter there except him, and he did only once a year. The Holy Spirit enlightened the chief priest with the knowledge that Mary, the chosen young girl, was worthy to enter the most sacred place. She was destined by God to become the Mother of the Son of God, Who would open the way for all people into the Kingdom of Heaven.
Fulfilling their promise, Joachim and Anna returned home, and Mary remained to live at the Temple. There She with other girls studied the Law of God and handiwork. She prayed a great deal, read the Holy Scriptures, and strictly observed the fasts. Mary lived at the Temple of God about eleven years, grew deeply devout in everything was submissive to God, and was extraordinarily meek and industrious.
The Most-holy Mary decided to consecrate Her entire life to the one God alone. For this, She vowed that She would never marry; that is She would remain a virgin forever. The Holy Spirit and holy angels protected the godly young girl.
The Entry into the Temple of the Most-holy Virgin Mary is celebrated in the Holy Orthodox Church on the 21st of November. This day is considered a great holy day, which in the hymns of the Church is called the harbinger of God’s good-will toward man. Starting with this holy day, we begin to sing "Christ is born... " during Matins.
Troparion of the Feast.
Today is the prelude of God’s good-will and the heralding of the salvation of mankind. The Virgin is presented openly, and She proclaimed Christ unto all. Then, with a great voice let us cry aloud: Rejoice, O Thou fulfilment of the Creator’s dispensation.
Note: Here is presented a short summary of the Birth of the Mother of God and Her childhood as described in Holy Tradition and piously preserved in the Holy Orthodox Church.
(from: The Law of God by Fr. Seraphim Slobodskoy)