Pope Abraham of Alexandria
Early life 
Abraham was Syrian by birth. He was a wealthy merchant who visited Egypt several times, and finally stayed there, residing in Alexandria. He was known for his goodness, devoutness, and love of the poor. After his ordination, he distributed half of his wealth to the needy and used the other half for building pools throughout Egypt, including the pool of Saint Mercurius in Cairo.
During the reign of Al-Muizz – who was the first Fatimid ruler of Egypt – the Islamic government was ambivalent in its treatment of the Copts, alternating sympathy and abuse with atrocity and brutality. At that time, St. Mark's Seat had been vacant for about two years. Finally the bishops and Coptic community leaders assembled in the Church of St. Serguis and Bacchus in Cairo in order to choose possible candidates. While they were convening, Abraham the Syrian, a man devoted to religion and piety, entered the church. One of the assembled turned to a bishop and said that if the bishop were looking for a candidate for the patriarchate, God had sent them a candidate. The whole group assembled was impressed by the selection, and they unanimously decided to elect him. They then took the protesting Abraham in iron fetters to Alexandria, where he was consecrated as the 62nd Patriarch of Alexandria.
Immediately upon taking office, Abraham suppressed the practice of simony which had become a significant problem during the last several patriarchates. He then turned his attention to the often degraded morals of the church archons, who frequently kept concubines as well as their legal wives. He went so far as to threaten anyone continuing to violate the sanctity of marriage with excommunication.
Moving of the Mokattam Mountain 
Al-Muizz was known for tolerance and interest in debates on religious matters. He had a Jewish minister named Yaqub ibn Killis, an Islamized Jew. He persuaded Al-Muizz to sponsor a debate between Abraham and a locally noted Jewish friend of ibn Killis' named Moses. Abraham brought with him Severus Ibn al-Muqaffa.
Ibn Killis informed Al-Muizz it was written in "the book of the Nazarenes" (meaning the New Testament) that, "If you have faith as a mustard seed, you will say to the mountain move from here to there, and it will move" (Matt. 17:20 & Mark 11:23). He showed this verse to the Caliph and persuaded him to challenge the Pope to order the Muqattam Mountain, east of Cairo, to move if he had as little faith as the small mustard seed. The Caliph sent for the Pope and asked him if such a verse really existed. When Pope Abraham affirmed that it was true, Al-Muizz challenged him to prove it or else the Copts would be subjected to the sword. The Pope asked for a three-day respite.
Abraham's Vision of the Virgin Mary 
He went directly to St. Mary's Church (Al Mu'allaqah, or "Hanging Church"), sent for bishops and priests and exhorted them to fast and pray for the duration of those three days. Before the dawn of the third day, the Pope, exhausted by grief and the long vigil he had kept, dozed off. It is said that Virgin Mary came to him in his sleep and inquired: "What is with you?" "My lady, you surely know what is happening," he replied. Thereupon, she comforted him and told him that if he went through the iron gate leading to the market, he would meet a one-eyed man carrying a sack of water. This is the man who would move the mountain, she said.
The Pope hurried out in the early morning to do as she said and he met Simon the Tanner. He asked Simon what he was doing at this early hour. To which Simon replied that he was carrying water to the sick and the old who could not fetch water for themselves. He said this was his practice every morning – to carry on his back a sack of water for the needy – before going to work at a hide tannery. When the Pope explained his purpose, Simon was reluctant at first but when he was told of the Pope's vision, he placed himself at his disposal.
The Miracle 
The two led a large gathering of the faithful and marched to the Mokattam Mountain. Beside them were the Caliph and his minister who had already incited many people against the Copts. Abraham celebrated mass and the multitude chanted after him kyrie layson (Coptic for "Lord have mercy"), pleading for God's mercy. It is said that they knelt down three times as the Pope made the sign of the cross with a sweeping gesture extending from one end of the mountain to the other.
The mountain shook violently as if a strong earthquake had hit the land. Then it began moving upwards. Every time the worshippers rose from their prayers, the mountain lifted itself upwards. When they knelt down, it also came down with a big bang. This happened three times and every time the mountain moved upwards, the rays of the sun, which was behind it, swept through the space separating the earth from the mountain and became clearly visible to the assembled crowd.
At this awesome sight, Al Muizz proclaimed, "God is Great!" Turning to Pope Abraham, he said, "This is enough to prove that your faith is true." Naturally, this miraculous event caused a tumult among the crowd. When order was re-established, Pope Abraham looked for Simon, who had kept himself hidden behind the Pope throughout the prayers, but he was nowhere to be found.
The Caliph, who was still shaking with fear, embraced the Pope warmly and this marked the beginning of a long friendship between the two. The Caliph asked the Pope to name his reward. After some hesitation, the Pope asked for permission to rebuild or renovate some churches, particularly that of St. Mercurius in Babylon in what is now Old Cairo. That church, which was partly destroyed, was being used as a sugar warehouse and the historic Church of al-Mu'allaqah. The Caliph offered funds from the state treasury for the reconstruction of the church but Abraham turned him down. "He whose Church we are building does not need the money of this world and is capable of helping us until we finish the job," Abraham said.
The Pope also decreed that the three-day grace period which he had requested from the Caliph, and which he and the bishops and priests spent in prayer and fasting, be a regular period of fasting to be observed by all Copts every year. Those three days were added to the forty days of fasting before Christmas. Thus, the Advent fasting became forty-three days starting on November 25.
Pope Abraham the Syrian departed in peace on 3rd of December, 978 A.D.
See also 
Pope Mina II of Alexandria
Pope Philotheos of Alexandria