Can you explain the tradition of Parayans and Saptahs and their historical significance according to the provided text?

The practice of performing Parayans (recitations) and Saptahs (week-long recitations) is described as a very ancient tradition, with roots tracing back to the Vedic era. As mentioned in Chapter 0, this custom is not only applied to great Sanskrit works like the Vedas and Ramayana but also to revered Marathi texts such as Shri Dnyaneshwari and Shri Dasbodh. These recitations can be of knowledge texts or biographies. This tradition is a cornerstone of Guru service, best performed through the study and recitation of detailed poetic Guru biographies.