Shiva Purana
सम्पूज्य पश्चात्सौराख्यं योगपीठं समर्चयेत् ॥ पीठोपरि समाकल्प्य मूर्त्तिं मूलेन मूलवित् ॥ २०॥
After worshiping the Lord one should worship the yoga seat called Saura. The root-knowing person places the idol on the flour with the root.
english translation
sampUjya pazcAtsaurAkhyaM yogapIThaM samarcayet ॥ pIThopari samAkalpya mUrttiM mUlena mUlavit ॥ 20॥
hk transliteration by Sanscript