“The Persian word didar is derived from didan means meeting, beholding or seeing. In Ismaili terminology, it denotes the beholding the Imam of the age. It is a means to strengthen the heart, cooling the eyes, refresh the faith and earn guidance and blessings of the Imam. When one is graced with the didar, he feels that he is newly born, and acts what the Imam imparted. The didar does not mean mere an act of looking the Imam. It needs the eyes of the knowledge and faith and without it the purpose does not solve. The Koran says, “And you see them looking towards you, yet they do not see” (7:198). It implies that there was much difference between the looking of the believers and unbelievers to the Prophet. Generally speaking, there are three types of didar: the exoteric (zahiri), esoteric (batini) and spiritual (noorani), but our discussion here covers only the exoteric didar.
It is related that once the Prophet was sitting in the mosque with his Companions and said, “There is only one person who earns the daily income of the world.” When asked, the Prophet pointed out towards a beggar who just entered the mosque and sat in a corner. The Companions came to him and asked, “What kind of business you are doing to earn one day’s income of the world.” He said, “I am mere a poor person. I have nothing else than these torn clothes I have put on. It is however my daily routine that when I leave my house in the morning, I first go to the house of Ali bin Abu Talib to behold him.” Meanwhile, the Prophet also joined them and said, “Beholding Ali gives reward equivalent to one day’s income of the world.” The Prophet also said, “To see Ali is also a worship.” Fakhruddin Razi in Tafsir al-Kabir (2:700), Muhibb al-Tabari in al-Riyad al-Nadirah (2:218), etc. report that the Prophet said: “Whoever wishes to see Adam in his knowledge, Noah in his piety, Abraham in his forbearance, Moses in his strength and Jesus in his worship and devotion, he should look at Ali bin Abu Talib.”
Describing his experience of a didar of Imam al-Mustansir billah in Cairo in 439/1048, al-Muayyad fid-din ash-Shirazi writes in his as-Sirat al-Muayyadiyah that, “I was taken near the place wherefrom I saw the bright Light of the Prophethood. My eyes were dazzled by the Light. I shed tears of joy and felt as if I was looking at the face of the Prophet of Allah and of the Commander of the Faithful, Ali. I prostrated myself before the one who is the fittest person to bow to. I wanted to say something, but 1 was awe-struck… I tried to speak but my tongue refused to move. People asked me to say what I wished to say. I could say nothing. The Imam said,