Shiva Purana
ध्यात्वा बाह्यक्रमेणैव पूजां निर्वर्तयेद्धिया ॥ समिदाज्यादिभिः पश्चान्नाभौ होमं च भावयेत् ॥ २० ॥
After meditating on the Lord, one should perform the worship in external order. Afterwards one should meditate on the navel with the sacrificial fire and other oblations.
english translation
dhyAtvA bAhyakrameNaiva pUjAM nirvartayeddhiyA ॥ samidAjyAdibhiH pazcAnnAbhau homaM ca bhAvayet ॥ 20 ॥
hk transliteration by Sanscript