Ezekiel 44:30-31

Complete Jewish Bible

³⁰ The first of all the firstfruits of everything, and every voluntary contribution of everything, from all your offerings, will be for the cohanim. You are also to give the cohen the first of your dough, so that a blessing will rest on your house. ³¹ The cohanim are not to eat anything, bird or animal, that dies naturally or is torn to death.