This is an edition of two texts by Abū ‘Abd al-Raḥmān al-Sulamī (d. 412/1021), one of the most important Ṣūfī authors. Al-Sulamī combined thorough knowledge of tradition (ḥadīth) with the Ṣūfī heritage. He paved the way for the gradual acceptance of Ṣūfism into the mainstream of Islamic thought, by endeavouring in much of his work to prove that Ṣūfism and Islam were mutually compatible. The texts in this edition present two important aspects of al-Sulamī’s writings. In the Jawāmi‘ adāb al-Ṣūfiyya (“A collection of Ṣūfī rules of conduct”), al-Sulamī provides us with what is apparently the first comprehensive documentation of Ṣūfī customs and practices. Most of the Jawāmi‘ consists of Ṣūfi sayings representing the views of five generations of thinkers. The subjects dealt with cover a wide range and reflect the preoccupations of Ṣūfī society. The second work is a handbook of spiritual discipline entitled ‘Uyūb al-nafs wa-mudāwātuhā (“The defects of the soul and their remedy”). As its title suggests, the ‘Uyūb deals with one of the central motifs of Ṣūfism, the constant struggle against the nafs, or the “lower soul”. The attitudes and beliefs expressed are on the whole characteristic of the early ascetics, who regarded the conduct of the Prophet as the supreme example. In both style and content, this work occupies the middle ground between the worlds of ḥadīth, adab, and ethics. The two texts contribute not only to a better appreciation of al-Sulamī’s work, but also to our understanding of a crucial phase in the history of Ṣūfism.