Mahabharata 5.177.2

5.177.2

kāśye kāmaṃ na gṛhṇāmi śastraṃ vai varavarṇini |
ṛte brahmavidāṃ hetoḥ kimanyatkaravāṇi te || 2 ||

"Bhishma said, 'O lord, repeatedly urged by that maiden to slay Bhishma, Rama replied unto that weeping girl, saying, 'O daughter of Kasi, O thou of the fairest complexion, I do not, on any account, take up arms now except for the sake of those that are conversant with the Vedas. Tell me, therefore, what else I can do for thee? Both Bhishma and Salwa are, O princess, exceedingly obedient to me. Do not grieve, I will accomplish thy object. I will not, however, O beautiful lady, take up arms, except at the command of Brahmanas. This hath been my rule of conduct.'