Shiva Purana
शिवविद्यात्मतत्त्वाख्यं तत्त्वत्रयमतः परम् ॥ सर्वासनोपरि सुखं विचित्रकुसुमान्वितम् ॥ १८ ॥
There are three elements beyond this, known as the Śiva-vidyā-atma-tattva. It was comfortable on all the seats and decorated with wonderful flowers.
english translation
zivavidyAtmatattvAkhyaM tattvatrayamataH param ॥ sarvAsanopari sukhaM vicitrakusumAnvitam ॥ 18 ॥
hk transliteration by Sanscript