Truth is the very nature of Sai
Speaking about the Shirdi Sai avatar, Swami said on March 4, 1962:
I am reminded of another instance. Some friends of Justice Rege came one day (for darshan), a mother and her little son. After an hour or so at Dwarakamayi, they went to listen to a puranic recital in the village. The pandit, much to the exasperation of the child, described Baba as an impostor and a fraud. The child insisted to the mother to move away from the place; it ran toward Baba and told him the whole story, when Baba asked them why they came back in such a hurry from the recital.
Baba laughed and said, “Yes, I am an ordinary man, not the Divine Power that you take me to be.” But the child could not be put off. He (the little boy) declared that Baba was God. Baba replied, “I am not God, little chap. See, my clothes are torn; I have only two hands; God should have four, isn’t it ?” But the boy was in no mood to agree. He declared that He was God, in spite of the two hands that He then seemed to lack.
Even while they were arguing thus, some others arrived, exulting over a miracle they witnessed. A child had slipped from the top floor of a house and escaped unhurt. Baba told them, “Yes, I held it in my four arms.” The boy jumped at the words and said, “Now you yourself agree that you have four hands and so you are God.”
Baba clasped the child to His bosom, and, taking it inside, gave him a vision of the Lord with four hands. Such was adherence to truth even in the previous body. It is not adherence, it is the very nature of Sai.
Source: Sathya Sai Speaks, Volume 2, Chapter 31.