You mean the one where he says that landlords (in the feudal sense, to be fair) are the only class in society which features the combination of the wits to recognize their own interests and interests aligned with the general interests of society, unlike both the mercantile (what we might now call capitalist) class, who knew their interests but whose interests were at odds with the broader society, and the laboring classes whose interests were the general interests, but who were too dull to know them and too easily misled by others?

Or some other Adam Smith quote?