Mbh 1.134.9

‘Vaisampayana continued, ‘On hearing these words, Drona reflected for a moment, and resolving upon the course of action he should follow, took Arjuna with him and went unto the Nishada prince. And he beheld Ekalavya with body besmeared with filth, matted locks (on head), clad in rags, bearing a bow in hand and ceaselessly shooting arrows therefrom. And when Ekalavya saw Drona approaching towards him, he went a few steps forward, and touched his feet and prostrated himself on the ground. And the son of the Nishada king worshipping Drona, duly represented himself as his pupil, and clasping his hands in reverence stood before him (awaiting his commands). Then Drona, O king, addressed Ekalavya, saying, ‘If, O hero, thou art really my pupil, give me then my fees.’ On hearing these words, Ekalavya was very much gratified, and said in reply, ‘O illustrious preceptor, what shall I give? Command me; for there is nothing, O foremost of all persons conversant with the Vedas, that I may not give unto my preceptor.’ Drona answered, ‘O Ekalavya, if thou art really intent on making me a gift, I should like then to have the thumb of thy right hand.’