गुकारः प्रथमो वर्णो मायादिगुणभासकः ।
रुकारोऽस्ति परं ब्रह्म मायाभ्रान्तिविमोचनम् ॥

The first sound body “Gu” in the sound “Guru” conveys the very essence of cosmic illusion. The second sound body “ru” is meant to destroy this cosmic illusion.

हेतवे जगतामेव संसारार्णवसेतवे ।
प्रभवे सर्वविद्यानां शम्भवे गुरवे नमः ॥

Obeisance to the venerable Guru who explains the mysteries of this worldly existence, who act as a bridge to enable the disciple to safely cross the ocean of worldly existence, who indeed is the father of all knowledge to be imparted to the disciple and who indeed is the very incarnation of the Lord Shiva or the Almighty.

-Above two verses & its meaning sourced from Shri Guru Gita by Swami Sahajananda

Shri Guru Gita  (Song of the Guru) , part of Skanda Purana, is authored by Sage Vyasa. Another view states that Shri Guru Gita is a part of Viswasara Tantra. The text of Shri Guru Gita describes a conversation between Lord Shiva and Mata Parvati, in which, Mata Parvati asks Lord Shiva about the significance of Guru in one’s life.  Lord Shiva explains the meaning of the word ‘Guru’ and importance of Guru in several verses. 

                                                                         . . . . .

फिर उठ खडा हुआ अचल

उत्साहित हो झूमा करता है ।

शन्का हैं इधर उधर की

हों ना जये फिर धराशायी,

भूल बैठा है पहचान अपनी

अब धीरे धीरे पग रखता है ।

नहीं जानता की सीमा है कितनी दूर ,

प्रतिदिन उठ चलना है,

हर प्रयास कर पर्वत जैसा बनना हैं ।

हर पथ ना होगा एक समान,

लगता जैसे है शत्रु बाहर ,

किन्तु है सम्पूर्ण रण स्वयम से ही,

भीतर ही मिलेगा प्रकाश अगर ढूंढ लिया स्वयम्भो को ही,

नहीं जानता की वो जो सब दख रहे है

क्षण प्रतिक्षण थामे वो मार्ग प्रदर्शित कर रहे ।।

Written these above lines many days ago, some random words of thought. To me only last two lines seems eternally true   .                             

My humble Obeisance to Swami ji. 

त्वमेव माता च पिता त्वमेव ।
त्वमेव बन्धुश्च सखा त्वमेव ।
त्वमेव विद्या द्रविणम् त्वमेव ।
त्वमेव सर्वम् मम देव देव ॥