A saintly sage is happy and pleasing in his external behavior, whereas internally he is most grave and thoughtful. Because his knowledge is immeasurable and unlimited he is never disturbed, and thus in all respects he is like the tranquil waters of the unfathomable and unsurpassable ocean.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
मुनिः प्रसन्नगम्भीरो दुर्विगाह्यो दुरत्ययः । अनन्तपारो ह्यक्षोभ्यः स्तिमितोद इवार्णवः
muniḥ prasannagambhīro durvigāhyo duratyayaḥ | anantapāro hyakṣobhyaḥ stimitoda ivārṇavaḥ
SB 11.8.5