Chapter 38 mentions different prescribed duties for different ages (yugas). Can you explain this concept and how it relates to the chapter's main message?

In Chapter 38, the text outlines a scriptural concept where the primary spiritual duty differs for each of the four ages, or yugas. It states that the recommended practice was Penance in the Krita age, Knowledge in the Treta age, and Sacrifice in the Dvapara age. For the current era, the Kali age, the chapter explicitly identifies Charity as the most effective and paramount spiritual practice. This framework is crucial because it elevates the chapter's central theme: the virtue of food donation (Annadan). By positioning charity as the highest duty for our times, Chapter 38 frames Sai Baba's practice of feeding people not merely as a kind act but as the most relevant and powerful spiritual discipline of the age.