What is the Principle of Non-Delegability?

What has been delegated cannot be delegated It is based upon the ethical principle that such delegated power constitutes not only as a right, but also as a duty to be performed by the delegate through the instrumentality of his own judgment and not through the intervening mind of another. A further delegation of such power, unless permitted by the sovereign power, would constitute a negation of this duty in violation of the trust reposed in the delegate.