A son born of a Brahmani wife by a Brahmana is unquestionably a Brahmana. One born of a Kshatriya wife or of a Vaishya wife, by a Brahmana husband, is likewise a Brahmana.
ब्राह्मण्यां ब्राह्मणाज्जातो ब्राह्मण: स्यान्न संशयः। क्षत्रियायां तथैव स्याद् वैश्यायामपि चैव हि॥