SB 11.3.42
evam prasnam rsin purvam
aprccham pitur antike
nabruvan brahmanah putras
tatra karanam ucyatam
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Once in the past, in the presence of my father, Maharaja Iksvaku, I placed a similar question before four great sages who were sons of Lord Brahma. But they did not answer my question. Please explain the reason for this.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
According to Srila Sridhara Svami the words brahmanah putrah, “the sons of Brahma,” refer to the four Kumaras headed by Sanaka Rsi. Srila Madhvacarya has quoted a verse from the Tantra-bhagavata stating that the reason the four sons of Lord Brahma, although mahajanas and experts in the science of devotional service, declined to answer King Nimi was that they wanted to demonstrate clearly that even those who are expert in the cultivation of speculative knowledge cannot understand the actual science of pure devotional service. Srila Jiva Gosvami has further commented that the sages avoided answering the question from the King because at that time King Nimi was a young boy and therefore not mature enough to understand the answer fully.