Mbh 9.51.9

"After that twelve year's drought had passed away, the great Rishis solicited one another for lectures on the Vedas. While wandering with famished stomachs, the Rishis had lost the knowledge of the Vedas. There was, indeed, not one amongst them that could understand the scriptures. It chanced that someone amongst them encountered Sarasvata, that foremost of Rishis, while the latter was reading the Vedas with concentrated attention. Coming back to the conclave of Rishis, he spoke to them of Sarasvata of unrivalled splendour and god-like mien engaged in reading the Vedas in a solitary forest. Then all the great Rishis came to that spot, and jointly spoke unto Sarasvata, that best of ascetics, these words, 'Teach us, O sage!' Unto them the ascetic replied, saying, 'Become ye my disciples duly!' The conclave of ascetics answered, 'O son, thou art too young in years!' Thereupon he answered the ascetics, 'I must act in such a way that my religious merit may not suffer a diminution! He that teaches improperly, and he that learns improperly, are both lost in no time and come to hate each other! It is not upon years, or decrepitude, or wealth, or the number of kinsmen, that Rishis found their claim to merit! He amongst us is great who is capable of reading and understanding the Vedas!'