Números 18:17

Mas el primogénito de vaca, y el primogénito de oveja, y el primogénito de cabra, no redimirás; santificados son: la sangre de ellos rociarás sobre el altar, y quemarás la grosura de ellos, ofrenda encendida en olor suave á Jehová.

But the firstling of a cow, or the firstling of a sheep, or the firstling of a goat, thou shalt not redeem; they are holy: thou shalt sprinkle their blood upon the altar, and shalt burn their fat for an offering made by fire, for a sweet savour unto the LORD.