We all know that the words Bhagavan and Ishwar are used in many Hindu scriptures. They give their meanings also. I want to know, in which scripture did the word "Bhagavan" appear first?
Most probably it appears first in Sri Rudram of the Yajur Vedas.
विकिरिद विलोहित नमस्ते अस्तु भगवः ।
यास्ते सहस्रँ हेतयोन्यमस्मन्निवपन्तु ताः ॥
विकिरिद- Destroyer of miseries like sin, disease, poverty etc., विलोहित- Of white complexion, भगवः- Possessor of six glories like wealth etc., ते- to you, नमः अस्तु- may prostration be. ते- Your, याः- which, सहस्रं हेतयः- thousands of weapons, ताः- those, अस्मत् अन्यं- our enemy (sin), निवपन्तु- may destroy.
The term ‘Vilohita’ has two meanings- of white complexion and of red complexion. As Parameswara is described to be of white complexion at some times and red at other times, both meanings apply here. As sin would lead to many miseries like poverty, disease etc., it is prayed that Parameswara should destroy the sins with his weapons.
Rishi of this mantra is Pulastya; Chandas is Trishtup; Devata is Sambhu.
सहस्राणि सहस्रधा बाहुवोस्तव हेतयः ।
तासामीशानो भगवः पराचीना मुखाकृधि ॥
भगव:- Bhagavan! तव- Your, बाहुवोः- in both hands, सहस्राणि- thousands of, हेतयः- weapons, सहस्रधा- are in many shapes. ईशानः- All-powerful you, तासां- of those weapons, मुखा- ends, पराचीना- not facing us, but turned away from us, कृधि- please do.
There are thousands of weapons in Parameswara’s hands. Each weapon has many characteristics. To indicate this, two terms ‘Sahasrani’ and ‘Sahasradha’ have been used. It is prayed that all those weapons be made to face away from us.
Rishi of this mantra is Narada; Devata is Sri Rudra; Chandas is Anushtup.
Mantras from Anuvaka 10.
Another Mantra I want to add here is a Rik Mantra dedicated Lord Rudra.
ayam me hasta bhagavan ayam me bhagavattarah | ayam me vishva bheshajah ayam me bhagattarah ||
This hand has all the healing powers of Bhagavan Shiva. This hand has a blessing touch (marshanah). Rig Veda 10.60.12
This is repeated in Atharva Veda too.