On Rules Regarding the Practical Part of the Medical Art had been labeled a copy of On Asthma by bio-bibliographer Moritz Steinchneider, but a closer examination of the manuscript by Gerrit Bos and Tzvi Langermann has revealed the treatise to be a previously unrecognized work of the great philosopher-physician Moses Maimonides. The publication of this translation marks the first time the Arabic manuscript with English translation has been available to a modern audience in any form. It is in Maimonides' favored aphoristic format and contains some unique advice on serious abdominal wounds, which is most likely a reflection on Maimonides' own experience with battlefield casualties.