Shiva Purana
तस्मात्सर्वप्रयत्नेन ब्राह्मणो धर्मतत्परः ॥ साधनं सर्ववर्गस्य रक्षेद्ब्राह्मण्यमुत्तमम् ॥ १८ ॥
Therefore a brahmin should be devoted to righteousness with all his efforts The means of all classes should be to protect the best of brahmins.
english translation
tasmAtsarvaprayatnena brAhmaNo dharmatatparaH ॥ sAdhanaM sarvavargasya rakSedbrAhmaNyamuttamam ॥ 18 ॥
hk transliteration by Sanscript