SB 3.1.10
yadopahuto bhavanam pravisto
mantraya prstah kila purvajena
athaha tan mantra-drsam variyan
yan mantrino vaidurikam vadanti
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
When Vidura was invited by his elder brother [Dhrtarastra] for consultation, he entered the house and gave instructions which were exactly to the point. His advice is well known, and instructions by Vidura are approved by expert ministers of state.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Political suggestions by Vidura are known as expert, just as, in modern times, Pandita Canakya is considered the authority in good counsel in both political and moral instructions.