This Feast is also know as Candlemas, and The Purification of Mary. The following hymn from Sacred Scripture establishes the event.
The Nunc Dimitis
8 When the days were completed for their purification 9 according to the law of Moses, they took him up to Jerusalem to present him to the Lord,
just as it is written in the law of the Lord, "Every male that opens the womb shall be consecrated to the Lord,"
and to offer the sacrifice of "a pair of turtledoves or two young pigeons," in accordance with the dictate in the law of the Lord.
Now there was a man in Jerusalem whose name was Simeon. This man was righteous and devout, awaiting the consolation of Israel, 10 and the holy Spirit was upon him.
It had been revealed to him by the holy Spirit that he should not see death before he had seen the Messiah of the Lord.
He came in the Spirit into the temple; and when the parents brought in the child Jesus to perform the custom of the law in regard to him,
he took him into his arms and blessed God, saying:
"Now, Master, you may let your servant go in peace, according to your word,
for my eyes have seen your salvation,
which you prepared in sight of all the peoples,
a light for revelation to the Gentiles, and glory for your people Israel."
The child's father and mother were amazed at what was said about him;
and Simeon blessed them and said to Mary his mother, "Behold, this child is destined for the fall and rise of many in Israel, and to be a sign that will be contradicted
(and you yourself a sword will pierce) 11 so that the thoughts of many hearts may be revealed."
There was also a prophetess, Anna, the daughter of Phanuel, of the tribe of Asher. She was advanced in years, having lived seven years with her husband after her marriage,
and then as a widow until she was eighty-four. She never left the temple, but worshiped night and day with fasting and prayer.
And coming forward at that very time, she gave thanks to God and spoke about the child to all who were awaiting the redemption of Jerusalem.
When they had fulfilled all the prescriptions of the law of the Lord, they returned to Galilee, to their own town of Nazareth.
The child grew and became strong, filled with wisdom; and the favor of God was upon him.
In this passage we meet a temple worker, the prophet named Simeon. He was promised by God that he wouldn't see death before seeing the fulfillment of the Promise, the coming of the Messiah.
This meeting takes place when Jesus is eight days old. In accordance with the Law he was consecrated at the temple. This rite recalls the Passover night in Egypt when God struck the firstborn in the Land of Egypt. Only those who painted the blood of a lamb on their doorposts were spared by the angel of death. It also prefigures the Crucifixion, when the Lamb of God, Jesus, will shed His blood that we might be spared eternal damnation.
We read in the Catholic Encyclopedia:
According to the Mosaic law a mother who had given birth to a man-child was considered unclean for seven days; moreover she was to remain three and thirty days "in the blood of her purification"; for a maid-child the time which excluded the mother from sanctuary was even doubled. When the time (forty or eighty days) was over the mother was to "bring to the temple a lamb for a holocaust and a young pigeon or turtle dove for sin"; if she was not able to offer a lamb, she was to take two turtle doves or two pigeons; the priest prayed for her and so she was cleansed. (Leviticus 12:2-8) Forty days after the birth of Christ Mary complied with this precept of the law.
Thus we celebrate this great Feast commemorating the continuing obedience of Mary which always reveals for us the Saviour Christ Jesus. Following her example, let each of us present to God our Heavenly Father and Creator our heart, our soul and our life through our obedience to His Divine Will. Then we will be purified. Then we, servants of the Lord, can go in peace.