… is from page 340 of F.A. Hayek’s October 1973 Wincott Memorial Lecture – titled “Economic Freedom and Representative Government” – as the text of this lecture appears as chapter 24 of Essays on Liberalism and the Economy (2022), which is volume 18 (expertly edited by Paul Lewis), of The Collected Works of F.A. Hayek:
It is a curious consequence of giving the representative assembly unlimited power that it has largely ceased to be the chief determining agent in shaping the law proper, but has left this task more and more to the bureaucracy.