What was the deeper significance of Sai Baba's comment about eating onions when he was observed by the visiting Yogi in Chapter 23?

The story in Chapter 23 recounts a Yogi who doubted Sai Baba's spiritual authority upon seeing Him eat simple bread and onions. Baba, being omniscient, perceived the Yogi's mental doubt and cryptically remarked, 'only those whose digestion is strong should eat onion. One who has the strength to digest it may eat onion freely.' This statement was not about physical digestion but was a profound spiritual metaphor. The 'onion' symbolized worldly things or practices that might seem impure to a conventional ascetic. Baba's comment implied that a true spiritual master possesses the 'digestive' strength to assimilate all experiences without being tainted, a concept the judgmental Yogi could not yet grasp. This lesson shattered the Yogi's pride, leading to his surrender.