What does it mean that Sai was the "Lord of Yoga"?

According to the text, calling Sai the "Lord of Yoga" signifies his complete spiritual mastery. Chapter 4 explains that he appeared on the banks of the Godavari river for the sake of uplifting the entire world. His yogic state involved realizing a profound sense of oneness, where he understood that "everything—moving and unmoving—is Brahman by nature." This means he saw no difference between himself and the rest of the universe. This realization brought supreme devotion and happiness, and his main goal was not worldly success but the "attainment of the Supreme," a state he helped others achieve as well.