Devibhagavatapurana 3.27.5

3.27.5

brāhmaṇī sarvakāryeṣu jayārthe nṛpavaṃśajā |
lābhārthe vaiśyavaṃśotthā matā vā śūdravaṃśajā ||

In all the cases, the Kumârîs, born of the Brâhmin families, can be taken; when victory is desired, the Kumârîs of the Kshattriya families are preferred; when profit is wanted, the Vais’ya Kumârîs and, when general welfare is wanted, the S’ûdra Kumârîs are to be taken.