The Wealth of Nations by Part 5 Chapter 2 Page 150

therefore, though the labourer might perhaps pay it out of his hand, could not properly be said to be even advanced by him; at least if tile demand for labour and the average price of provisions remained the same after the tax as before it. In all such cases, not only the tax but something more than the tax would in reality be advanced by the person who immediately employed him. The final payment would in different cases fall upon different persons. The rise which such a tax might occasion in the wages of manufacturing labour would be advanced by the master manufacturer, who would both be entitled and obliged to charge it, with a profit, upon the price of his goods.

The final payment of this rise of wages, therefore, together with the additional profit of the master manufacturer, would fall upon the consumer.