In 18th Chapter of BG, we find following verses -
The Lord abides in the hearts of all beings, O Arjuna, causing all of them to revolve by His power as if they were mounted on a machine. 61
Run to him for shelter with your whole being, O BhArata. By his grace you will attain the highest peace and the eternal abode. 62
Lord Krishna in just few 2-3 verses before, were asking Arjuna to mentally surrendering all actions to him(i.e Krishna) but suddenly he starts referring someone else to go for shelter in the above verses.
But again after 2-3 verses he changes pronoun and declare as follows -
Abandoning all other dharmas, come to Me alone for shelter. Do not grieve, for I will relieve you from all sins. 66
i.e, he changed the pronouns as I -> Him -> I within handful of verses.
Now, In the unique Kashmiri Shaiva commentary on Bhagwat Geeta by AchArya Abhinavupta he comments on this as follows -
... By the statement take refuge in him, and by my grace, the Lord brings together the nature of Parmeshvara, Ishvara and VAsudeva.
Although I couldn't understand whole paragraph (which I have omitted as ...), I am only curious to know this sentence only. Who exactly is Parmeshvara, Ishvara & Vasudeva? And what is the distinction? Do any scripture from any school of thought say anything on this?