How did Sai Baba prove his omniscience to Laxmichand?

Sai Baba demonstrated his omniscience, or inner knowledge, to Laxmichand on multiple occasions as described in Chapter 28. The first instance was when Laxmichand mentally wished for khaja, and Baba promptly ordered that very sweet to be brought as an offering. A second, more striking example occurred when Laxmichand silently wondered if Baba's persistent cough was due to an 'evil eye.' The very next morning, Baba remarked aloud, 'Yesterday I had much coughing; is this the effect of an evil eye?' This direct echo of Laxmichand's private thought astonished him, making him realize that Baba knows everything and 'dwells in everyone's heart.'