How did Sai Baba demonstrate his omniscience to Sapatnekar and what promise did he make to him?

Sai Baba demonstrated his omniscience in a profound way. As Sapatnekar was marveling at how Baba could know his entire life story, Baba read his thoughts. Chapter 48 recounts that Baba pointed at him and exclaimed, "He says I killed his child; he is accusing me of this!" Baba then refuted the accusation and made a solemn promise, saying he would bring a son to Sapatnekar's lap, just as he had restored Ramdas to his mother. Baba placed his hand on Sapatnekar's head, telling him his worries were gone and that he would soon be successful if he had full faith. This entire exchange showed Sapatnekar that Baba was a "great knower of the inner self."