It is said that the Buddhists pray by machinery; that they put prayers into a wheel, and unroll them by the length. This notion arises from a misconception. Saky'a-muni, the Buddha, is said to have “turned the wheel of the law” —i,e. to have preached Buddhism incessantly- we should say as a horse in a mill.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894