Valmiki Ramayana Bala Kanda Sarga 56 Shloka 1
Original Shlokaएवमुक्तो वसिष्ठेन विश्वामित्रो महाबल:। आग्नेयमस्त्रमुत्क्षिप्य तिष्ठ तिष्ठेति चाब्रवीत्।।1.56.1।।
1 source checked for this shloka
महाबल: mighty, विश्वामित्र: Visvamitra, वसिष्ठेन by Vasishta, एवम् thus, उक्त: having been addressed, आग्नेयम् अस्त्रम् Agneya astra, उत्क्षिप्य after lifting, तिष्ठ तिष्ठ इति 'stay, stay' so, अब्रवीत् said.
Thus said Vasishta. Mighty Viswamitra lifted up agneya astra (shaft of fire) and discharging it said, 'stay, stay'. Vasishta destroys the weapons employed by Viswamitra with his Brahmadanda -- Viswamitra undertakes austerities to acquire brahminhood.