By virtue of her asceticism, veracity, and devotion to her lord she it is that can consume Fire, but Fire cannot burn her.
तपसा सत्यवाक्येन अनन्यत्वाच्च भर्तरि। असौ विनिर्दहेदग्नि न तामग्निः प्रधक्ष्यति ॥