Based on Chapter 28 of the Shri Sai Satcharitra, what defines a Sadguru and what is the extent of their compassion?

According to Chapter 28, a Sadguru like Sai is one who is proficient in both Shabda-Brahma (the divine word) and shows the signs of Para-Brahman (the Supreme Being). A Sadguru is established in their own true nature and has the ability to impart teachings to disciples. The chapter emphasizes that a Guru's compassion is profound, even exceeding that of a father. While a father gives birth to a physical body that is subject to the cycle of birth and death, the Guru's "additional compassion" is demonstrated by their ability to remove both birth and death, thereby liberating the devotee from this cycle.