There is no need to take shelter of unnecessary literature or concern oneself with many so-called philosophers and thinkers who are useless for spiritual advancement. Nor should one accept a disciple for the sake of fashion or popularity. One should be callous to these so-called sastras, neither opposing nor favoring them, and one should not earn one’s livelihood by taking money for explaining sastra. A sannyasi must always be neutral and seek the means to advance in spiritual life, taking full shelter under the lotus feet of the Lord.

Quoted in Srila Prabhupada’s purport to SB 7.13.7