Kautilya's Arthashastra 3.6.24

3.6.24

kṣetre vā janayed asya niyuktaḥ kṣetrajaṃ sutam /
mātṛbandhuḥ sagotro vā tasmai tat pradiśed dhanam //E

Or on the wife of such a Bráhman shall a sagotra, relative bearing the same family name, or a (mátribandha) relative of his mother, beget a natural son (kshetraja), and this son may take that wealth.