महापुराण ४ · Tamasika
The great scripture of Shaiva devotion, telling of Shiva's nature, the Jyotirlingas, the marriage of Shiva and Parvati, the birth of Ganesh and Kartikeya, and the power of the Shivling, rudraksha and the name 'Om Namah Shivaya'. (Some lists name the Vayu Purana in this place.)
शिव भक्ति का महान ग्रंथ – शिव का स्वरूप, बारह ज्योतिर्लिंग, शिव-पार्वती विवाह, गणेश-कार्तिकेय जन्म तथा शिवलिंग, रुद्राक्ष और पंचाक्षर मंत्र की महिमा।
A story from this Purana
Brahma and Vishnu once argued over who was greater. A limitless column of fire appeared between them; Vishnu dived down as a boar and Brahma flew up as a swan, yet neither found its end. Shiva emerged from the pillar – the origin of the Linga and of Mahashivratri.