Guru Gobind Singh Ji's Commentary on Gita - Gobind Gita
Within the Gobind Gita, Guru Gobind Singh Ji not only includes his own commentary on the Bhagavad Gita but also of a commentary named the Gūḍārtha Dīpikā, written by Madhusudhana Saraswati (1540-1640). Madhusudhana was famous for writing Advaita Vedanta texts, including the very famous Advaitasiddhi. This gives us a glimpse into the kind of library which Guru Gobind Singh was utilizing, along with the scholarly prowess to engage with such difficult Sanskrit material.
The verse below is Guru Gobind Singh summing up Madhusudhana's commentary on the 38th Salok of the Second Chapter of the Bhagavad Gita. Below this translation is part of Madhusudhana's commentary translated into English from Sanskrit by S. K. Gupta.
ਹਰਖ ਸੋਗ ਤੇ ਰਹੈ ਅਤੀਤ ॥ ਸਮ ਕਰਿ ਜਾਨੈ ਵੈਰੀ ਮੀਤ ॥ ਐਸੇ ਮਧਸੂਦਨ ਜੀ ਗਾਏ ॥ ਜਗਤ ਲੋਕ ਕੇ ਗਾਇ ਸੁਨਾਏ ॥
Those who remain unattached to both pain and pleasure, they recognize all as one, even enemies and friends. This is what Madhusudhana Saraswati has sang, which has been recited and expounded upon by countless people in the world.
Gobind Gita, Chapter Two
"There should be no attachment to pleasure and its two immediate causes namely loss and defeat. If Arjuna can drive away the craving for pleasures or the desire to avert pain and plunge into the campaign as a duty, as something compulsorily enjoined by his code of conduct, he will avoid all sin stemming from slaying of superiors or Brahmins or from failure to perform mandatory works, for to him fighting is mandatory. Contrarily he who takes up arms from motives of gain or victory will be responsible for sins stemming from violence. The fugitive incurs sin for non-performance of mandatory duty. So actions performed with non-attachment are unsullied by evil results. Conquest of territory or empyrean bliss are just subsidiary effects."
Madhusudhana Saraswati on the Bhagavad Gita: Sisir Kumar Gupta, page 42.