Shiva Purana
खनित्वा देवयजनं दण्डमात्रप्रमाणतः ॥ प्रणवव्याहृतिभ्यां च प्रोक्ष्य चास्तीर्य्य च क्रमात् ॥ ५१ ॥
Digging a sacrifice for the gods the size of a rod Sprinkle and spread the oṁkāra with the oṁkāra and spread it in order.
english translation
khanitvA devayajanaM daNDamAtrapramANataH ॥ praNavavyAhRtibhyAM ca prokSya cAstIryya ca kramAt ॥ 51 ॥
hk transliteration by Sanscript