That's the French proverb for "Slow and steady wins the race".
Rich [Hickey] makes the point that sprinters run fast, but not long. Then he says that Agile "solved" this problem by just firing the starting gun over and over again in quick succession. He grins, and the audience laughs. Then he goes on to say that continuous sprinting does not necessarily makes systems simple, and simplicity is the real key to speed.
That is exactly the issue I have with Scrum and other so-called "agile" methods. It sacrifices long-term design and overall quality for fast short-term hacks. Sometimes there are no shortcuts for long hard work to end up with something simple.
Simple and easy are not interchangeable concepts...