Shiva Purana
तत्त्वत्रयमयं साक्षाद्विद्यामूर्तिं सदाशिवम् ॥ मूर्तिमूलेन संकल्प्य सकलीकृत्य च क्रमात् ॥ ३५ ॥
This threefold element is directly the embodiment of knowledge and is always known as Sadaśiva. Resolving at the root of the idol and making it all together in order.
english translation
tattvatrayamayaM sAkSAdvidyAmUrtiM sadAzivam ॥ mUrtimUlena saMkalpya sakalIkRtya ca kramAt ॥ 35 ॥
hk transliteration by Sanscript