Guru Purnima is a day which honours the revered sage Vyasa, who arranged the Vedas, wrote the Brahma Sutras, the Mahabharata and the Srimad Bhagavatam.
It is a day to honour one’s Guru, and Great Gurus and Sages that have helped humanity.
The day is also to honour and awaken the Guru within. The Guru is that which dispels ignorance, and helps one be free of ego and its attachments. It is auspicious to chant the Holy name on this Day.
In the Srimad Bhagavatam, there is a discussion between an Avadhuta (Dattatreya) and the King Yadhu about what the Avadhuta has learnt and who his Gurus were. The Avadhuta mentions 24 Gurus including earth, air, sky, water, fire, moon, sun, pigeon, python; the ocean, moth, honeybee, elephant, the deer, the fish, the prostitute Pingala, the kurara bird (Hawk), the child; the young girl, arrow maker, serpent, spider and the wasp.
Here are just five of the gurus mentioned (One can read the entire text in the Srimad Bhagavatam)
People when they are harassed should understand that things are happening helplessly under the control of providence, and thus he should never be distracted from progress on his dharma. This rule I have learned from the earth.
A wise man should learn from the mountain to devote all his efforts to the service of others and to make the welfare of others the sole reason for his existence. Similarly, as the disciple of the tree, he should learn to dedicate himself to others.
Every person is surrounded by innumerable material objects, which possess good and bad qualities. However, one who has transcended material good and evil should not become entangled even when in contact with the material objects; rather, he should act like the wind. Though the wind may carry various sweet and bad scents, it is never contaminated by it and the scent neither belongs to the breeze.
A thoughtful sage, even while living within a material body, should understand himself to be pure spirit soul. Similarly, one should see that the spirit soul enters within all forms of life, both moving and nonmoving, and that the individual souls are thus all-pervading. The sage should further observe that the Supreme Person as the Supersoul, is simultaneously present within all things. Both the individual soul and the Supersoul can be understood by comparing them to the nature of the sky: although the sky extends everywhere and everything rests within the sky, the sky does not mix with anything, nor can it be divided by anything.
Although the mighty wind blows clouds and storms across the sky, the sky is never implicated or affected by these activities. Similarly, the spirit soul is not actually changed or affected by contact with the material nature. Although the living entity enters within a body made of earth, water and fire, and although he is impelled by the three modes of nature created by eternal time, his eternal nature is never actually affected.
O King, a wise man is just like water because he is free from all contamination, gentle by nature, and by speaking creates a beautiful vibration like that of flowing water. Just by seeing, touching or hearing such a saintly person, the living entity is purified, just as one is cleansed by contact with pure water. Thus a saintly person, just like a holy place, purifies all those who contact him because he always chants the glories of the Lord.
Saintly persons become powerful by execution of austerities. Their firmness is unshakable because they do not have anything to do with the material world. Such naturally liberated sages accept foodstuffs that are offered to them by destiny, and if by chance they happen to eat contaminated food, they are not affected, just like fire, which burns up contaminated substances that are offered to it.
A wise man sometimes appears in a concealed form and at other times reveals himself like fire hidden in the woods. For the welfare of the jivatma who desire real happiness, a wise man may accept the worshipable position of guru, and thus like fire he burns to ashes all the past and future sinful reactions of his worshipers by mercifully accepting their offerings.”
Guru is Dharma, the Highest Path.