The great Manu, O king of kings, has written two Slokas. As regards your duties, O you of Kuru's race, you should always remember them. Fire has originated from water, the Kshatriya from the Brahmana, and iron from stone. The three, viz., fire, Kshatriya, and iron, can act on every other thing, but coming into contact with their respective origins, their force becomes neutralised.