hat tip: Mystagogy (read it all there!)
The Feast of Mid-Pentecost is celebrated for an entire week until the following Wednesday, making it an eight day feast. During this entire time the hymns of Mid-Pentecost are joined with that of Pascha. Because of the theme of water, traditionally the Church celebrates the Lesser Blessing of the Waters on this day, preferably with a procession with the Holy Cross to a water spring.The theme of the feast not only invokes water, but even more central to the Gospel chronology it honors Christ as Teacher and Wisdom as He reveals Himself between the stories of the Paralytic and that of the Blind Man. During this time we are told: “Now about the middle of the feast Jesus went up into the temple, and taught… Jesus answered them, and said, ‘My doctrine is not mine, but his that sent me. If any man will do his will, he shall know of the doctrine, whether it be of God, or whether I speak of myself'” (John 7:14-30). The icon for this feast depicts the young Jesus teaching the elders in the Temple (Luke 2:46, 47) at which time Jesus first revealed Himself as a teacher or rabbi. Traditional Orthodox icons will depict Jesus as larger than the elders, showing his superior spiritual status.Since the hymns of the Church invoke and praise our Lord as the Wisdom of God spoken of in the Book of Proverbs, it is traditional that all churches named after Holy Wisdom or Hagia Sophia celebrate their feast on this day. In fact, Greek scholar Constantine Kalokyre has written a study titled “The Churches of the Wisdom of God and the Date of their Celebration”, which appeared in the periodical Saint Gregory Palamas, no. 71 (723) (1988), pp. 538-617. In this study he comes to the conclusion that the Great Church of Hagia Sophia in Constantinople celebrated its feast day on Mid-Pentecost.