Vaishnava Dharmashastra 18.25

18.25

atha brāhmaṇasya kṣatriyasya vaiśyasya vā vaiśyaśūdrau putrau syātāṃ, tadā taddhanaṃ tridhā vibhajeyātām ||

Again, if there are two sons of a Brâhmana or a Vaisya or a Sûdra, and the one belongs to the Vaisya, the other to the Sûdra caste, they shall divide the estate into three parts;