Now let's answer the question: The Vedic origin of Lord Shiva: which means from Rudra to Shiva?
Let's get some facts in place:
Now, in the Rig Vedā, the word “Śiva” occurs more than 30 times, and all these are not personified names (swarūpa), they are various aspects of auspiciousness and pleasantness. For example, the hymn “Be Śiva with me” meaning be ...
Here is the reference from Mahabharata.
Bhishma said, "Thou art endued with great intelligence, O
Yudhishthira! It is even so as thou sayest. The person is very rare
who is possessed of all those good qualities. To be brief, conduct
like this (viz., the presence of all the virtues spoken of), is very
difficult to be met with even upon careful search. I ...