Can you explain the story of Prajapati's one-syllable instruction 'Da' and how Sai Baba applies this teaching?

According to Chapter 14, Prajapati gave a one-syllable instruction, 'Da,' to his three children: the gods, demons, and humans. The gods, who are self-controlled, understood it as 'Danta' (be self-controlled). The demons, who are violent, understood it as 'Daya' (be merciful). Humans, who are gripped by greed, understood it as 'Dana' (give charity). Baba applies this teaching by using the letter 'Da' to ask His devotees to be merciful, give charity, and be self-controlled. This is presented as the Guru's simple, one-syllable remedy for the disciple's faults, helping them attain extreme happiness.