Mahabharata 1.158.52

1.158.52

arjuna uvāca |
yadi prītena vā dattaṃ saṃśaye jīvitasya vā |
vidyā vittaṃ śrutaṃ vāpi na tadgandharva kāmaye || 52 ||

"On hearing these words of the Gandharva, Arjuna said, 'O Gandharva, if from satisfaction for having obtained thy life at my hands in a situation of danger, thou givest me thy science, and these horses, I would not accept thy gift.' The Gandharva replied, saying, 'A meeting with an illustrious person is ever a source of gratification; besides thou hast given me my life. Gratified with thee, I will give thee my science. That the obligation, however, may not all be on one side, I will take from thee, O Vibhatsu, O bull in Bharata's race, thy excellent and eternal weapon of fire!'