Hilkhot Niddah of the Ramban (Rabbi Moshe ben Nachman) consists of 9 chapters, each made up of short paragraphs explaining the definitions and practical applications of different aspects of the laws of niddah (a woman in her menstrual cycle or experiencing particular discharges). The author explains in his introduction that he wrote this short practical guide only upon request, after initially protesting that there were already sufficient books on the subject, such as the Ra’avad’s Ba’alei HaNefesh. His rulings are frequently quoted by later legal authorities, though many did not have access to this work until after its first printing in 1741, as part of a collection entitled Todat Shelamim. The work has been reprinted numerous times, often alongside Ba’alei HaNefesh (which was also included in Todat Shelamim).