Imam Ali (peace be upon him): Imam Hasan (peace be upon him) asked his noble father to show him the excellence and honour that Allah had bestowed upon him. The hadith is recounted until he says: The Commander of the Faithful (peace be upon him) commanded the wind, and the wind carried us to Mount [Qaf]. When we reached it, we suddenly saw a mountain of green emerald upon which stood an angel in the form of an eagle. When his gaze fell upon the Commander of the Faithful (peace be upon him), he said: "Peace be upon you, O successor and vicegerent of the Messenger of the Lord of the worlds, and His caliph. Will you permit me to ask a question?" The Imam (peace be upon him) returned his greeting and said: "If you wish, ask; and if you wish, I shall tell you what it is you want to ask me about." The angel said: "You tell me, O Commander of the Faithful (peace be upon him)!" The Imam (peace be upon him) said: "You wished to seek my permission to visit Khidr (peace be upon him)." The angel said: "Yes, it is so!" He said: "I have granted you permission." The angel said بِسْمِ اللهِ الرَّحْمنِ الرَّحِیم [In the Name of Allah, the All-Beneficent, the All-Merciful] and departed swiftly. We walked there for a while, and the angel, after visiting Khidr (peace be upon him), returned to his place. Salman (may Allah have mercy on him) said: "O Commander of the Faithful (peace be upon him)! I see that that angel visited Khidr (peace be upon him) only with your permission!" The Imam (peace be upon him) said: Allah is the One who raised up the heavens without any pillars that you can see (Ra'd/2). Not one of these angels moves from his place for a moment without my permission. The rank and station of my son Hasan (peace be upon him), and after him my son Husayn (peace be upon him), and then nine descendants from the progeny of Husayn (peace be upon him) is likewise — the ninth of whom is the Qa'im of the family of Muhammad (may Allah hasten his noble relief). We asked: "What is the name of the angel appointed over Mount Qaf?" He said: "Tarja'il." We asked: "O Commander of the Faithful (peace be upon him)! How do you come here every night and return?" He said: "In the same way that I brought you here. By the One who split the seed and created the breeze! I know things of the dominion of the heavens and the earth such that your hearts could not bear the knowledge of even one of them. The Greatest Name of Allah, the Mighty and Majestic, consists of seventy-two letters. Asaf ibn Barkhiya knew only one letter of it. When he called upon Allah with that letter, Allah caused the earth between him and the throne of Bilqis to sink and removed the distance until he took the throne of Bilqis. Then, in the blink of an eye, the earth returned to its original state. By Allah! We know seventy-two letters of it, and only one letter of the knowledge of the unseen has Allah reserved for Himself — and there is no power and no strength except in Allah, the Most High, the Most Great. Whoever wished, recognized us, and whoever wished, denied and belied us. [Those who ought to know us have known us]."