For the maintenance of public force and the expenses of administration, a common contribution is indispensable. It must be equally apportioned among all citizens according to their abilities.
Gist of Idea
Everyone must contribute to the state's power and administration, in just proportion
Mirabeau and committee (Declaration of the Rights of Man , 13)
Presumably this enshrines graduated income tax, an eighteenth century invention. Could you contribute just by your labour, or by fighting for the army? Those may be greater contributions than mere money.
'Les Philosophes', ed/tr. Torrey,Norman L. [Perigee 1980], p.286