The "Foreteller"1 Icon of the Mother of God is located in the katholikon (cathedral church) of Konstamonitou Monastery on Mount Athos, and it became famous in the following way.
On August 1, 1020, the eve of the monastery’s Feast Day (The Transfer of the Relics of the Protomartyr Stephen from Jerusalem to Constantinople), the Ecclesiarch Father Agathon, (Zacharias in the Schema) was overcome with great sorrow. The Monastery’s Altar Feast was approaching, and its supplies were so depleted that there was not enough oil to light the church lamps for the solemn celebration.
That night, Father Agathon prayed before the Icon of the Mother of God with fervent tears. So earnestly did he beg her to help the monastery that he became exhausted. Sitting down before the Icon, he fell asleep at once. In a dream he heard a voice coming from the holy Icon telling him not to grieve, because the church vessels were now filled with oil, and the pantries contained everything that was necessary for the monastery's continued existence.
When Father Agathon awoke, he wondered if what he had been told in his dream was true. Hastening to the vessel where the oil was stored, he was overjoyed when he saw that it was filled to the brim. At once, he reported his vision to Igoumen Hilarion, the Superior of Konstamonitou Monastery, and to all the brethren.
Everyone went to inspect the pantries and discovered that all the necessary supplies were there in abundance. They rejoiced because now, unexpectedly, they could light the church lamps for the service. Led by Igoumen Hilarion, they served the Vigil and sang praises to the Queen of Heaven for the miracle she had performed.
After this event, the wonderworking Icon of the Mother of God, before which Father Agathon had prayed, was known as the "Foreteller." Now she is placed in the Monastery's katholikon, on the wall, on the right hand side. Ever since this miracle took place, an "unsleeping" oil lamp remains lit before the Icon.
In his most informative book Bogomater (an account of the earthly life of the Mother of God, and of her wonderworking Icons), Eugene Poselyanin (+ February 13, 1931) states that there are two other Icons of the Theotokos on the Holy Mountain which are also called "Foreteller" - the "Paramythia," or "Consolation" Icon of Vatopaidi Monastery (January 21), and the Zographou Icon "Of the Akathist" (October 10).
1 In Greek: Παναγία η Αντιφωνήτρια. In Russian: Предвозвестительница