Mbh 13.47.4b

Hence, O best of kings, the son born of the Brahmana wife must be regarded as the first in rank and superior to the son born of the Kshatriya wife. Because, again the Kshatriya is not equal in point of birth to the Brahmana wife, hence the son of the Brahmana wife takes one after another, all the best things, O Yudhishthira, among his father's possessions. Similarly, the Vaisya cannot be regarded as the equal of the Kshatriya in point of birth. Prosperity, kingdom, and treasury, O Yudhishthira, belong to the Kshatriya. All these have been ordained for the Kshatriya. The whole earth, O king, with her belt of seas, is seen to belong to him. By following the duties of his own order, the Kshatriya acquires an extensive affluence. The sceptre of royalty is held by him. Without the Kshatriya, O king, there can be no protection. The Brahmanas are highly blessed, for they are the deities of the very deities. Following the ordinances laid down by the Rishis, the Kshatriyas should worship the Brahmanas according to due rites. Even this is the eternal usage. Coveted by thieves and others, the possessions of all men are protected by Kshatriyas in the observance of the duties assigned to their order. Indeed, wealth and spouses and every other possession owned by people would have been forcibly taken away but for this protection that the Kshatriyas afford. The Kshatriya, as the king, becomes the protector or rescuer of all the others. Hence, the son of the Kshatriya wife shall, without doubt, be held to be superior to him that is born of the Vaisya wife. The son of the Kshatriya wife, for this, takes a larger share of the paternal property than the son of the Vaisya mother."