Shiva Purana
तदुक्तेनैव धर्मेण शैवास्त्रैवर्णिका नराः ॥ तस्माद्विमुकुतिमन्विच्छञ्च्छिवमेव समाश्रयेत् ॥ ४७ ॥
Men are classified under three castes in accordance with their duties. Hence he who wishes for liberation shall resort to Śiva alone.
english translation
taduktenaiva dharmeNa zaivAstraivarNikA narAH ॥ tasmAdvimukutimanvicchaJcchivameva samAzrayet ॥ 47 ॥
hk transliteration by Sanscript