Ramayana
असौ पुनर्व्याकरणं ग्रहीष्यन्सूर्योन्मुखः प्रष्टुमना कपीन्द्रः । उद्यद्गिरेरस्तगिरिं जगाम ग्रन्थं महद्धारयनप्रमेयः ॥ 7-36-46 ॥
Moreover this lord of the monkeys, the immeasurable one, desiring to master grammar and intent on questioning the Sun, facing toward him and bearing a great treatise, traveled from the mountain of the rising sun to the mountain of its setting.
english translation