Ulumuna Vol. 26, No. 1, 2022, p. 145-173 Journal of Islamic Studies Published by State Islamic University Mataram p-ISSN 1411-3457, e-ISSN 2355-7648, available online at https://ulumuna.or.id Copyright © 2022_Ulumuna_this publication is licensed under a CC BY-SA 145 KITAB RUKUN ISTINJAK: Integration of Fiqh and Sufism in the Early 19th Century of West Borneo Hinterland Faizal Amin IAIN Pontianak, Indonesia Email: faizalamin@iainptk.ac.id Abstract: Kitab Rukun Istinjak [Book on the Procedure for Cleaning the Private Parts after Relieving Oneself] is a manuscript that originated from interior Borneo of West Kalimantan in the early 19th century. The text describes the concepts of fiqh [Islamic jurisprudence], which provides not only technical explanations for the implementation of rituals but also a description of philosophical concepts for the consumption of the heart/soul. The context of the private collection of manuscripts is for a minimal audience, namely the sālik [follower of Sufism] who study and practice the teachings of Sufism in the way of Nūr Muḥammad [Light of Muhammad]. This Rukun Istinjak manuscript records Islamic teachings, which show the integration of Islamic jurisprudence into Islamic mysticism, which initially developed in hinterland Borneo. Even though the text indicates the existence of Sufistic-style Islamic teachings adopted by the indigenous Muslim community of West Kalimantan in the Putussibau area, in particular, there are no clues that explain their affiliation or relations with a specific tariqa order. Keywords: Malay manuscript; sālik; fiqh; mysticism; mushāhada; Nūr Muḥammad. DOI: http://dx.doi.org/10.20414/ujis.v26i1.485 Introduction DISCUSSING Islam Nusantara [Islam of the Indonesian Archipelago or Indonesian Islamic Model] is discussing Islam as part of a social phenomenon that continues to change, not as an absolute and always relevant doctrine (ṣāliḥ li kulli zamān wa-makān). Islam Nusantara is a civilization that is an inseparable part of the Islamic