This article presents and analyzes a new source on the relationship between ḥadīth and Sufism, a juzʾ in the library of the University of Leipzig titled Juzʾ fīhi qiṣṣat al-ʿAbbās b. Ḥamza maʿa Dhī l-Nūn al-Miṣrī raḥmat Allāh ʿalayhi, “An Encounter of al-ʿAbbās b. Ḥamza with Dhū l-Nūn al-Miṣrī.” The text is an account of the visit of Abū l-Faḍl al-ʿAbbās b. Ḥamza b. Ashūsh of Nishapur (d. 288/901) to Dhū l-Nūn al-Miṣrī (d. ca 245/859-860), an influential figure in the early mystical tradition. By underlying the difference between a mainstream ḥadīth transmission and what the text calls ḥadīth al-riqāq (“heart-melting traditions”), the text helps to defend early ascetics and mystics against accusations of being “weak transmitters” of prophetical traditions.