Srimad Bhagavatam Canto 03, Chapter 04, Text 26

SB 3.4.26

uddhava uvaca
nanu te tattva-samradhya
 rsih kausaravo ’ntike
saksad bhagavatadisto
 martya-lokam jihasata
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
Sri Uddhava said: You may take lessons from the great learned sage Maitreya, who is nearby and who is worshipable for reception of transcendental knowledge. He was directly instructed by the Personality of Godhead while He was about to quit this mortal world.
 
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
Although one may be well versed in the transcendental science, one should be careful about the offense of maryada-vyatikrama, or impertinently surpassing a greater personality. According to scriptural injunction one should be very careful of transgressing the law of maryada-vyatikrama because by so doing one loses his duration of life, his opulence, fame and piety and the blessings of all the world. To be well versed in the transcendental science necessitates awareness of the techniques of spiritual science. Uddhava, being well aware of all these technicalities of transcendental science, advised Vidura to approach Maitreya Rsi to receive transcendental knowledge. Vidura wanted to accept Uddhava as his spiritual master, but Uddhava did not accept the post because Vidura was as old as Uddhava’s father and therefore Uddhava could not accept him as his disciple, especially when Maitreya was present nearby. The rule is that in the presence of a higher personality one should not be very eager to impart instructions, even if one is competent and well versed. So Uddhava decided to send an elderly person like Vidura to Maitreya, another elderly person, but he was well versed also because he was directly instructed by the Lord while He was about to quit this mortal world. Since both Uddhava and Maitreya were directly instructed by the Lord, both had the authority to become the spiritual master of Vidura or anyone else, but Maitreya, being elderly, had the first claim to becoming the spiritual master, especially for Vidura, who was much older than Uddhava. One should not be eager to become a spiritual master cheaply for the sake of profit and fame, but should become a spiritual master only for the service of the Lord. The Lord never tolerates the impertinence of maryada-vyatikrama. One should never pass over the honor due to an elderly spiritual master in the interests of one’s own personal gain and fame. Impertinence on the part of the pseudo spiritual master is very risky to progressive spiritual realization.
Srimad Bhagavatam Canto 03, Chapter 04, Text 25
Srimad Bhagavatam Canto 03, Chapter 04, Text 27