As is in Shri Sai Satcharita, by Hemadpant .. Chapter II Page 10

Om Sai Shri Sai Jaya Jaya Sai

Mr. Dabholkar was present on this occasion and he thought that this was the answer Baba gave to the question whether Guru was a necessity (Vide Sai Leela Vol I, No. 5, Page 47); and he thereupon took the hint that no discussion of the problem, whether man is free or bound, is of any use in spiritual matters, but that on the contrary real Paramartha is possible only as the result of the teachings of the Guru, as is illustrated in this chapter of the original work in the instances of great Avatars like Rama and Krishna, who had to submit themselves to their Gurus, Vasishtha and Sandipani respectively, for getting self-relization and that the only virtues necessary for such progress are faith and patience.  (Vide Sai Satcharita, Ch. II, 191-92).

Bow to Shri Sai - Peace be to all