Isaiah 58:3

Why have we fasted, they say, and You do not see it? Why have we afflicted ourselves, and You take no knowledge [of it]? Behold [O Israel], on the day of your fast [when you should be grieving for your sins], you find profit in your business, and [instead of stopping all work, as the law implies you and your workmen should do] you extort from your hired servants a full amount of labor.