Ramayana
सर्वासु विद्यासु तपोविधाने प्रस्पर्धते ऽयो हि गुरुं सुराणाम् । सो ऽयं नवव्याकरणार्थवेत्ता ब्रह्मा भविष्यत्यपि ते प्रसादात् ॥ 7-36-48 ॥
In all branches of knowledge and in the practice of austerity he vies indeed with Brihaspati, the preceptor of the gods; this knower of the meaning of the nine grammars will, by your grace, become even a Brahma.
english translation