Shiva Purana
तं हत्वा स महाकालो ज्योतिर्लिंगस्वरूपतः ॥ देवैस्स प्रार्थितोऽतिष्ठत्स्वभक्तपरिपालकः ॥ १६ ॥
After killing him, on being requested by the gods; lord Mahākāla stayed there in the form of a Jyotirliṅga. He continues to protect his devotees.
english translation
taM hatvA sa mahAkAlo jyotirliMgasvarUpataH ॥ devaissa prArthito'tiSThatsvabhaktaparipAlakaH ॥ 16 ॥
hk transliteration by Sanscript