Shiva Purana
इदमासनमित्युक्त्वा चासनानि प्रकल्पयेत् ॥ प्रणवादिद्वितीयांते स्वस्य नाम समुच्चरन् ॥ ८ ॥
Saying this is the seat, one should arrange the seats. At the end of the second oṁkāra he chanted his own name.
english translation
idamAsanamityuktvA cAsanAni prakalpayet ॥ praNavAdidvitIyAMte svasya nAma samuccaran ॥ 8 ॥
hk transliteration by Sanscript