Why wouldn't Sai Baba give a mantra to the woman who asked? Did his own Guru give him one?

Sai Baba explains in Chapter 19 that he could not give a mantra, or 'upadesh', because his own Guru never gave one to him. Despite serving his Guru for twelve years with the strong desire to receive a secret instruction, it never happened. Baba states, "my Guru did not blow any mantra into my ears, so how can I blow one into yours?" Instead of a verbal mantra, his Guru's grace was transmitted through his loving gaze, like a mother tortoise caring for her young from afar. Baba advised the woman that the effort of a mantra was useless in this context and that simply paying attention to him would bring her spiritual wealth.