According to the teachings in Chapter 52, why is meditating on Sai's physical (Saguna) form important for spiritual realization?

Chapter 52 emphasizes the importance of the Saguna, or form-based, path to spiritual understanding. It states that without first entering the Saguna form, the light of the Self cannot be known. The text posits that the ultimate reality, Parabrahma, which is without attributes, is entirely difficult to grasp directly. Therefore, by meditating 'immensely on Sai's physical form,' the devotee can progress. As this meditation deepens, the subtle nature of the Self will manifest just as the focus on the physical form (Saguna) eventually vanishes, leading the devotee mysteriously toward the supreme goal.