Bhishma said The dignity of a Brahmana, O Yudhishthira, cannot be acquired by a person belonging to any of the three other castes. That dignity is the highest with respect to all creatures.
भीष्म उवाच ब्राह्मण्यं तात दुष्प्राप्यं वर्णैः क्षत्रादिभिस्त्रिभिः। परं हि सर्वभूतानां स्थानमेतद् युधिष्ठिर॥