Ascending on the mountain-top or on the terrace of a palace, or proceeding to a wilderness devoid of trees and plants, one should, in secrecy, mature his counsels. O Bharata, neither a friend who is without learning, nor a learned friend who hath no control over his senses, deserveth to be a repository of state secrets. O king, never make one thy minister without examining him well, for a king’s finances and the keeping of his counsels both depend on his minister.

In plain words: Vidura tells King Dhritarashtra to make important plans in private places, like a mountain top or an empty field. Do not share secrets with a friend who lacks learning, or with a learned friend who cannot control himself. Test a person well before making him your adviser, because your money and your secrets depend on him.