Stumbled upon today:
This book is an exhaustive survey of the Buddha’s exhortations from the Pali Canon addressed in the form “thus … should you train yourselves” (evañhi vo … sikkhitabbaṃ). The passages are organized by theme and roughly follow the gradual path taught in the MahāAssapurasutta (MN 39). In addition to outlining a gradual course, this sutta is one of the primary sources for this type of injunction.