In the Preamble of the U. S. Constitution and section 8. "Promote the general welfare".  See also: Common Good.
General Welfare. The concern of the government for the health, peace, morality, and safety of its citizens. Providing for the welfare of the general public is a basic goal of government. The preamble to the U.S. Constitution cites promotion of the general welfare as a primary reason for the creation of the Constitution. 

Although it's not stated directly it is implicit: capable of being understood from something else though unexpressed.