Ramayana
प्रजापतिस्तुं तां प्राप्तां प्राह वाक्यं सरस्वतीम् । वाणि त्वं राक्षसेन्द्रस्य भव या देवतेप्सिता ॥ 7-10-43 ॥
The Lord of Creatures spoke these words to Sarasvati, who had arrived: "O Speech, become for this lord of the rakshasas such an utterance as the gods desire."
english translation