How did Sai Baba prove his omniscience to Laxmichand beyond just fulfilling his desire for a sweet?

Sai Baba demonstrated his inner knowledge (antaryami) to Laxmichand on multiple occasions, revealing that he knew Laxmichand's unspoken thoughts and physical discomforts. Chapter 28 recounts that while Laxmichand was suffering from intense hunger and back pain, Baba spoke words that directly mirrored his condition: "Hunger has come, that's good. There should be medicine for back pain." In another instance, when Laxmichand silently wondered if Baba's cough was caused by an evil eye, Baba echoed this very thought the next morning. These events showed Laxmichand that Baba was an 'echo without sound,' fully aware of the innermost thoughts and feelings of his devotees.