This is a warning for those who have bought the Prometheus edition of the Wealth of Nations by Adam Smith. It is abridged, and it seems to have been edited to the effect that Adam Smith appears as a market liberal. The following quotes are from the original book and are not found in the Prometheus edition. Judge yourself whether you would attribute these quotes to Smith.
No tax can ever reduce, for any considerable time, the rate of profit in any particular trade which must always keep its level with other trades in the neighbourhood. (book 5, chapter 2)
Civil government, so far as it is instituted for the security of property, is in reality instituted for the defence of the rich against the poor, or of those who have some property against those who have none at all. (book 5, chapter 1)