Mind is called the superior instrument. Mind alone is the instrument for human beings for being bound or being delivered. By mind should the self be elevated, not degraded. Mind is the friend as well as the foe; of this there is no doubt. When human being wins over his mind on the strength of the intellect and with devotion to Sri Hari, then it becomes his friend; there are no other enemies, thus in Brahmavaivartaka Puraana.
अनात्मन: means unconquered, unrestrained mind. If the mind is not restrained, then it is not likely to be helpful; just as one having a servant who does no work, like one having no servant at all. His self, the mind becomes an adversary like an enemy.
Tatparya Nirnaya :- Jiva, the self elevates himself from this life with the help of the Supreme Self. Sri Vishnu, ever a kinsman to the noble ones and enemy for the evil ones. That means, to the one who is devoted to the Lord, he acts as his friend through grace; for others he is enemy. In the latter part of the sentence it is shown that Supreme Self abides within (such person).