Indian Penal Code, 1860
Whoever voluntarily causes hurt, if the hurt which he intends to cause or knows himself to be likely to cause is grievous hurt, and if the hurt which he causes is grievous hurt, is said "voluntarily to cause grievous hurt". Explanation.-A person is not said voluntarily to cause grievous hurt except when he both causes grievous hurt and intends or knows himself to be likely to cause grievous hurt. But he is said voluntarily to cause grievous hurt, if intending or knowing himself to be likely to cause grievous hurt of one kind, he actually causes grievous hurt of another kind. Illustration A, intending of knowing himself to be likely permanently to disfigure Z's face, gives Z a blow which does not permanently disfigure Z's face, but which causes Z to suffer severe bodily pain for the space of twenty days. A has voluntarily caused grievous hurt.