הלכה על ביצה 26:7

And [it] is practiced in every place and at all times by males and females. And one who transgresses it volitionally is stoned, and that is when there are witnesses and a warning there. [Let] this rule be in your hand always - that the death penalty or lashes is only administered with witnesses and a warning - and the warning is always to distinguish between [the] inadvertent and [the] volitional. And know this fundamental and do not ask from me to review it. And if he did thoughtful work (melekhet machshevet) inadvertently, he brings a fixed sin offering (Beitzah 13b).