Shiva Purana
तस्माच्चतुर्गुणः प्रोक्तः शिव एव मुनीश्वराः॥ स एव सगुणो ज्ञेयः शक्तिमत्त्वाद्द्विधापि सः ॥ २१॥
O great sages, thus Śiva is fourfold. He alone shall be known as Saguṇa. In view of the possession of Śakti he is twofold.
english translation
tasmAccaturguNaH proktaH ziva eva munIzvarAH॥ sa eva saguNo jJeyaH zaktimattvAddvidhApi saH ॥ 21॥
hk transliteration by Sanscript