Ramayana
एतदेव हि काव्यं ते काव्यानामुत्तमं श्रुतम् । सर्वं विस्तरतो राम व्याख्यास्यति न संशयः ॥ 7-98-16 ॥
This very poem of yours is heard to be the foremost among poems, O Rama, and it shall expound everything in full detail—of that there is no doubt.
english translation