Isn't it contradictory that Baba first says 'leave the worry about milk entirely to me' but then warns against thinking 'that I should do the exercises and you should drain the cups of milk'?

These statements from Chapter 19 are not contradictory but complementary, illustrating a nuanced spiritual lesson about effort and grace. The first statement, 'You start doing the exercises (Zor); leave the worry about milk entirely to me,' is Sai Baba's assurance that if a devotee puts in sincere, dedicated effort (the 'exercises'), the Guru will unfailingly provide the necessary grace and support (the 'milk'). The second statement clarifies this by warning against a lazy or entitled attitude where the devotee expects all the benefits without doing any of the work. As Chapter 19 explains, 'one should be alert for the sake of the task.' The lesson is that divine grace does not eliminate the need for personal responsibility and action; rather, it empowers and rewards it, aligning with the chapter's core secret: 'As the action, so the hearing; as the practice, so the benefit.'