The unswerving resolve (dhṛti) by which, through discipline (yoga), one sustains the activities of the mind, vital breaths (prāṇa), and senses, That resolve (dhṛti), O son of Pritha (Pārtha), is of goodness (sāttvikī).
When it sustains acts of mind, breath, and senses through discipline without wavering, resolve is lucid.
(33) The constancy by which a man holds fast in check the works of mind and breath and sense, unswerving in spiritual exercise, is constancy in Goodness' way.
18.33 O Pārtha, the firmness that is unfailing through concentration, with which one restrains the functions of the mind, vital forces and the organs, that firmness is born of sattva.
18.33 That Dhṛti (fortitude or persisting perseverance) by which one maintains the unswerving activities of the mind and vital force and these sense-organs through Yoga --- that Dhṛti is of the nature of Sattva.
18.33 The unwavering firmness by which, through Yoga, the functions of the mind, the life-force and the senses are restrained -- that firmness, O Arjuna, is Sattvic (pure).