Vaishnava Dharmashastra 18.12

18.12

atha brāhmaṇasya brāhmaṇakṣatriyau putrau syātāṃ, tadā saptadhā kṛtād dhanād brāhmaṇaś caturo 'ṃśān ādadyāt ||

Again, if there are two sons of a Brâhmana, the one belonging to the Brâhmana and the other to the Kshatriya caste, they shall divide the estate into seven parts; and of these the Brâhmana son shall take four parts;