Can you explain the concepts of 'shraddha' and 'saburi' using the information in the provided chapters?

Based on the provided source chunks, it is not possible to explain the concepts of 'shraddha' and 'saburi'. The text does not mention or define these terms. Instead, the preface in Chapter 0 discusses the composition and use of spiritual texts, specifically Guru biographies. It explains that these books can be studied for two primary purposes: 'Kamya', which is for worldly prosperity or relief from troubles, and 'Nishkam', which is for achieving liberation from the cycle of birth and death. The text also notes that writing and reciting these biographies is a form of ancient and highly regarded Guru service.