Also Capital 3 in regards to The Trinity Formula:

Capital — profit (profit of enterprise plus interest), land — ground-rent labour — wages this is the trinity formula which comprises all the secrets of the social production process. [compare with Ricardo "The produce of the earth -- all that is derived from its surface by the united application of labour, machinery, and capital, is divided among three classes of the community; namely, the proprietor of the land, the owner of the stock or capital necessary for its cultivation, and the labourers by whose industry it is cultivated.", and "the laws which regulate this distribution [as in 'the proportions of the whole produce of the earth which will be allotted to each of these classes, under the names of rent, profit, and wages'], is the principal problem in Political Economy ]

... The actual wealth of society and the possibility of constantly expanding its reproduction process, therefore, do not depend upon the duration of surplus-labour, but upon its productivity and the more or less copious conditions of production under which it is performed. In fact, the realm of freedom actually begins only where labour which is determined by necessity and mundane considerations ceases; thus in the very nature of things it lies beyond the sphere of actual material production Just as the savage[sic] must wrestle with Nature to satisfy his wants, to maintain and reproduce life, so must civilised man, and he must do so in all social formations and under all possible modes of production. With his development this realm of physical necessity expands as a result of his wants; but, at the same time, the forces of production which satisfy these wants also increase. Freedom in this field can only consist in socialised man, the associated producers, rationally regulating their interchange with Nature, bringing it under their common control, instead of being ruled by it as by the blind forces of Nature; and achieving this with the least expenditure of energy and under conditions most favourable to, and worthy of, their human nature. But it nonetheless still remains a realm of necessity. Beyond it begins that development of human energy which is an end in itself, the true realm of freedom which, however, can blossom forth only with this realm of necessity as its basis. The shortening of the working-day is its basic prerequisite.

Also a good quote if people say that work gives dignity and is important. Marx didn't like wage labour and had a conception of work which included doing fun art things and lining your body with paint before rolling naked over each other while describing a Dungeons and Dragons session.