what is the deep meaning of this Gita quote?
Sloka 67 of Chapter 2 of BG relates to pure SPIRITUAL aspects.
If we start with Sloka 62 of Chapter 2 of BG, we can understand that they are related to PURE SPIRITUAL aspects, meant for persons proposing to be/already engaged in SPIRITUAL pursuits.
ध्यायतो विषयान्पुंसः सङ्गस्तेषूपजायते।
सङ्गात् संजायते कामः कामात्क्रोधोऽभिजायते।।2.62।।
In the case of a person who dwells on objects, there arises attachment for them. From attachment grows hankering, from hankering springs anger.
क्रोधाद्भवति संमोहः संमोहात्स्मृतिविभ्रमः।
स्मृतिभ्रंशाद् बुद्धिनाशो बुद्धिनाशात्प्रणश्यति।।2.63।।
From anger follows delusion; from delusion, failure of memory; from failure of memory, the loss of understanding; from the loss of understanding, he perishes.
नास्ति बुद्धिरयुक्तस्य न चायुक्तस्य भावना।
न चाभावयतः शान्तिरशान्तस्य कुतः सुखम्।।2.66।।
The man who cannot fix his mind in meditation cannot have knowledge of the Self. The unsteady man cannot practise meditation. He cannot have even intense devotion to Self knowledge nor can he have burning longing for liberation or Moksha.
He who does not practise meditation cannot possess peace of mind. How can the man who has no peace of mind enjoy happiness?
Desire or Trishna (thirsting for sense objects) is the enemy of peace. There cannot be an iota or tinge of happiness for a man who is thirsting for sensual objects. The mind will be ever restless? and will be hankering for the objects. Only when this thirsting dies? does man enjoy peace. Only then can he meditate and rest in the Self.
Then comes the sloka 67.
इन्द्रियाणां हि चरतां यन्मनोऽनुविधीयते।
तदस्य हरति प्रज्ञां वायुर्नावमिवाम्भसि।।2.67।।
That mind, which is allowed by a person to be submissive to, i.e., allowed to go after the senses which go on operating, i.e., experiencing sense-objects, such a mind loses its inclination towards the pure self. The meaning is that it gets inclined towards sense-objects. Just as a contrary wind forcibly carries away a ship moving on the waters, in the name manner wisdom also is carried away from such a mind. [The idea is that the pursuit of sense pleasures dulls one's spiritual inclination, and the mind ultimately succumbs to them unresisting.]
These are related to keeping the senses fixed on Meditating on God, without allowing the senses wandering here and there.
Note: “The question: what is the deep meaning of this Gita quote?” is licensed by Stack Exchange Inc (https://hinduism.stackexchange.com/); user contributions licensed under CC BY-SA.