SB 8.20.1
sri-suka uvaca
balir evam grha-patih
kulacaryena bhasitah
tusnim bhutva ksanam rajann
uvacavahito gurum
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Sri Sukadeva Gosvami said: O King Pariksit, when Bali Maharaja was thus advised by his spiritual master, Sukracarya, his family priest, he remained silent for some time, and then, after full deliberation, he replied to his spiritual master as follows.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Srila Visvanatha Cakravarti Thakura remarks that Bali Maharaja remained silent at a critical point. How could he disobey the instruction of Sukracarya, his spiritual master? It is the duty of such a sober personality as Bali Maharaja to abide by the orders of his spiritual master immediately, as his spiritual master had advised. But Bali Maharaja also considered that Sukracarya was no longer to be accepted as a spiritual master, for he had deviated from the duty of a spiritual master. According to sastra, the duty of the guru is to take the disciple back home, back to Godhead. If he is unable to do so and instead hinders the disciple in going back to Godhead, he should not be a guru. Gurur na sa syat (Bhag. 5.5.18). One should not become a guru if he cannot enable his disciple to advance in Krsna consciousness. The goal of life is to become a devotee of Lord Krsna so that one may be freed from the bondage of material existence (tyaktva deham punar janma naiti mam eti so ’rjuna). The spiritual master helps the disciple attain this stage by developing Krsna consciousness. Now Sukracarya has advised Bali Maharaja to deny the promise to Vamanadeva. Under the circumstances, therefore, Bali Maharaja thought that there would be no fault if he disobeyed the order of his spiritual master. He deliberated on this point — should he refuse to accept the advice of his spiritual master, or should he independently do everything to please the Supreme Personality of Godhead? He took some time. Therefore it is said, tusnim bhutva ksanam rajann uvacavahito gurum. After deliberating on this point, he decided that Lord Visnu should be pleased in all circumstances, even at the risk of ignoring the guru’s advice to the contrary.
Anyone who is supposed to be a guru but who goes against the principle of visnu-bhakti cannot be accepted as guru. If one has falsely accepted such a guru, one should reject him. Such a guru is described as follows (Mahabharata, Udyoga 179.25):
guror apy avaliptasya
karyakaryam ajanatah
utpatha-pratipannasya
parityago vidhiyate
Srila Jiva Gosvami has advised that such a useless guru, a family priest acting as guru, should be given up, and that the proper, bona fide guru should be accepted.
sat-karma-nipuno vipro
mantra-tantra-visaradah
avaisnavo gurur na syad
vaisnavah svapaco guruh
“A scholarly brahmana expert in all subjects of Vedic knowledge is unfit to become a spiritual master without being a Vaisnava, but if a person born in a family of a lower caste is a Vaisnava, he can become a spiritual master.” (Padma Purana)