Canto 1 - Boyhood
Bāla-kāṇḍa
Chapter 56: King Viśvāmitra Decides to Become a Brāhmaṇa
Text 1.56.12-13

एतान्यस्त्राणि चिक्षेप सर्वाणि रघुनन्दन।
वसिष्ठे जपतां श्रेष्ठे तदद्भुतमिवाभवत्॥

तानि सर्वाणि दण्डेन ग्रसते ब्रह्मणः सुतः।
तेषु शान्तेषु ब्रह्मास्त्रं क्षिप्तवान्गाधिनन्दनः॥

etāny astrāṇi cikṣepa sarvāṇi raghu-nandana
vasiṣṭhe
japatāṁ śreṣṭhe tad adbhutam ivābhavat

tāni sarvāṇi daṇḍena grasate brahmaṇaḥ sutaḥ
teṣu
śānteṣu brahmāstraṁ kṣiptavān gādhi-nandanaḥ

etāni = these; astrāṇi = weapons; cikṣepa = he threw; sarvāṇi = all; raghu-nandana = O descendant of Raghu; vasiṣṭhe = at Vasiṣṭha; japatām śreṣṭhe = the best of mantra reciters; tat adbhutam iva abhavat = that appeared astonishing; tāni sarvāṇi = all of them; daṇḍena = with his staff; grasate = devoured; brahmaṇaḥ sutaḥ = Brahmā’s son; teṣu śānteṣu = when all of were neutralized; brahmāstram = the Brahmāstra; kṣiptavān = threw; gādhi-nandanaḥ = the son of Gādhi.

O descendant of Raghu, he threw all these weapons at Vasiṣṭha, the best of mantra reciters. That appeared astonishing. Brahmā’s son devoured all of them with his staff. When all of those weapons were neutralized, the son of Gādhi threw the Brahmāstra.

It is indicated here that because Vasiṣṭha was the best of mantra reciters he was able to devour all the weapons that were hurled at him using his brahminical staff. This is the power of reciting mantras. That Viśvāmitra could hurl those weapons without exerting himself even slightly was astonishing to see.