The Ṣúfí Shaykhs demand from each other the fulfilment of the duties of companionship and enjoin their disciples to require the same, so that amongst them companionship has become like a religious obligation. The Shaykhs have written many books explaining the rules of Ṣúfí companionship; e.g., Junayd composed a work entitled _Taṣḥíḥ al-irádat_,[165] and Aḥmad b. Khaḍrúya of Balkh another, entitled _Al-Ri`áyat bi-ḥuqúq_[166] _Allah_,[167] and Muḥammad b. `Alí of Tirmidh another, entitled _Ádáb al-murídín_.[168] Other exhaustive treatises on this subject have been written by Abu ´l-Qásim al-Ḥakím,[169] Abú Bakr al-Warráq, Sahl b. `Abdalláh (al-Tustarí), Abú `Abd al-Raḥmán al-Sulamí, and Master Abu ´l-Qásim Qushayrí. All those writers are great authorities on Ṣúfiism, but I desire that my book should enable anyone who possesses it to dispense with other books and, as I said in the preface, be sufficient in itself for you and for all students of the Ṣúfí doctrine. I will now classify in separate chapters their various rules of discipline relating to conduct. Footnote 165: “The Rectification of Discipleship.” Footnote 166: So all the texts, instead of the correct _li-ḥuqúq_. Footnote 167: “The Observance of what is due to God.” Footnote 168: “Rules of Conduct for Disciples.” Footnote 169: _Nafaḥát_, No. 129. _Chapter concerning the Rules of Companionship._ Since you have perceived that the most important thing for the novice is companionship, the fulfilment of its obligations is necessarily incumbent on him. Solitude is fatal to the novice, for the Apostle said, “Satan is with the solitary, but he is farther away from two who are together;” and God hath said, “_There is no private discourse among three persons but God is the fourth of them_” (Kor. lviii, 8). I have read in the Anecdotes that a disciple of Junayd imagined that he had attained to the degree of perfection, and that it was better for him to be alone. Accordingly he went into retirement and withdrew from the society of his brethren. At nightfall a camel used to appear, and he was told that it would take him to Paradise; on mounting it, he was conveyed to a pleasant demesne, with beautiful inhabitants and delicious viands and flowing streams, where he stayed till dawn; then he fell asleep, and on waking found himself at the door of his cell. These experiences filled him with pride and he could not refrain from boasting of them. When Junayd heard the story he hastened to the disciple’s cell, and having received from him a full account of what had passed, said to him: “To-night, when you come to that place, remember to say thrice, ‘There is no strength or power but in God, the High, the Great.’” The same night he was carried off as usual, and though in his heart he did not believe Junayd, by way of trial he repeated those words thrice. The crew around him shrieked and vanished, and he found himself seated on a dunghill in the midst of rotten bones.