Bhagavad Gita Chapter 9 - Rajavidya Rajaguhya Yoga - Sloka 17

The entire content of this mail is from Swami Chidbhavananda's translation of Bhagavad Gita, published by Ramakrishna Mission

Iswara is Everything 16-19

1 Gita Sloka  every day - Chapter 9 - Rajavidya Rajaguhya Yoga - Sloka 17

Pita aham asya jagatah mata dhata pitamah I

Vedyam pavitram aumkarah rk sama yajuh eva cha II sloka 17

पिता अहं अस्य जगतः माता धाता पितामहः  I 

वेद्यं पवित्रं औम्कारः ऋक साम यजुः एव च II श्लोक 17

I am the father of this world, the mother, the dispenser, and the grandfather; I m the knowable, the purifier, the syllable Om and also rik, sama & yajus.

God being the source of the universe and the beings in it, he is held as the father, mother and the grandfather. Each individual is rewarded by the lord according to his efforts and therefore he is the dispenser. Knowing iswara, everything comes to be known in its perspective; the lord is therefore knowable. 

The elements earth, water, fire and air have the power to purify the things brought in contact with them. Man gets purified as he contacts God;God is therefore the most efficacious purifier.

The rik, sama and yajus deal with the origin, sustenance and end of the prakriti. No mention is made here of atharva, the fourth veda as it doesnot come up to the level of the other three in orthodoxy.

Languages are all based on the science of sound. In this respect the vedas may be said to have reached perfection. They are sacred books which proclaim that sound is the seed from which the universe comes into being. Sound is god, nada brahman.  He persists eternally as the syllable Om, which is a blending of a+u+m. Sound originates as a, sustains as u and terminates as m. By the creator uttering Om once the universe is created, maintained and withdrawn.