क्षिप्रं भवति धर्मात्मा शश्वच्छान्तिं निगच्छति । कौन्तेय प्रतिजानीहि न मे भक्तः प्रणश्यति ॥
kṣipraṃ bhavati dharmātmā śaśvaccāhāntiṃ nigacchati | kaunteya pratijānīhi na me bhaktaḥ praṇaśyati ||
Translation
Quickly such a person becomes of righteous self and attains lasting peace. O son of Kunti, know for certain that My devotee is never lost.
Interpretation
Once the heart turns truly to the Divine, transformation is rapid (kshipram — quickly). The person becomes dharmatma (one of righteous self) and attains shashvata shanti (lasting peace). And then the promise: 'na me bhaktah pranashyati' — my devotee is never lost. Never. This is the unconditional guarantee of divine grace. It mirrors the earlier teaching of verse 6.40 (no one who does good comes to grief) but elevates it: specifically the devotee of the Divine will never be abandoned or lost. Krishna asks Arjuna to declare this (pratijaneehi — 'know for certain and declare it') as truth.