Bhagavad Gītā Chapter Six verse 6

bandhur ātmā ’tmanas tasya yenātmāivātmanā jitaḥ |
anātmanas tu śatrutve vartetātmāiva śatruvat ||

citta - psyche (the totality of the human mind, conscious and unconscious); mind; heartātman - essence; the highest personal principle of life; the individual soul, selftasya - its, of it, of thisanātman - other than essence

Commentaries and Reflections

Commentary by T Krishnamacharya:

When dominated by KleśaCitta is not a friend.

Commentary by TKV Desikachar:

Only the Citta is the cause for Bandhana or Mokṣa.