Once, a boy went to a gurukula to learn the Vedas. The sage, a renowned authority in the shastras, told him it would take 12 years to complete his studies.

Determined to get an education in the holy scriptures, the boy was not to be deterred. He was duly enrolled and began his stay in the gurukula as a Brahmachari.

The years went by in rigorous exercises of academic discipline, listening to learned discourse and intensive study. At the end of 12 years, it was time for the disciple to be tested. Only after clearing it would he be pronounced at the samavarthanam ceremony as a graduate learned in the four Vedas.

On the appointed day, the disciple presented himself before his master. The sage, however, told him of a sudden engagement that had come up. He then asked the young man to go to the backyard, stand under an ancient tree and recite selected portions of the Vedas.

Mystified, the disciple wanted to know what purpose would be served by such exercise. “Once you complete reciting, the tree will shed some leaves. You must count their number,” his master said. “What has that got to do with my test?”
“It is not an ordinary tree! The number of fallen leaves will signify the number of errors you committed during your recital,” the sage explained.

So the young man prepared to take the test under the designated tree. He knew he had to invoke Lord Ganesha at the beginning. But the moment he did so, all the leaves fell down together.

The baffled disciple rushed to his master and narrated the incident. In a trice, the sage divined what had happened.
“Before invoking Lord Ganesha or any other deity, did you meditate upon your guru?”, he asked.

The young man was ashamed. At that instant, he understood that the guru is the compassionate soul who opens the seeker’s inner eye, bestows him with knowledge, sets him on the right path.

Verily, the preceptor is the incarnation of the Lord Himself. Which is why pupils must take to heart the noble exhortation — Guru Brahma, Guru Vishnu, Guru Maheswar.
— the harbinger