According to Saint Luke's Gospel (2: 22) the Virgin Mary and Joseph took the Christ Child to the temple in order that Mary should undergo the ceremony of purification, essential under Mosaic law after giving birth to a child. At the same time a sacrifice was to be made, giving thanks for a first-born son.
The reference to the Virgin's purification leads immediately to the meeting with Simeon and has become conflated in painting with the Presentation in the Temple.