Srimad-Bhagavatam: Canto 8 - Chapter 1 - Verse 39
Sanskrit:
अर्चित्वा गन्धमाल्याद्यै: पयसा स्नपयेद् विभुम् ।वस्त्रोपवीताभरणपाद्योपस्पर्शनैस्तत: ।गन्धधूपादिभिश्चार्चेद्द्वादशाक्षरविद्यया ॥ ३९ ॥
ITRANS:
arcitvā gandha-mālyādyaiḥpayasā snapayed vibhumvastropavītābharaṇa-pādyopasparśanais tataḥgandha-dhūpādibhiś cārceddvādaśākṣara-vidyayā
Translation:
In the beginning, the devotee should chant the dvādaśākṣara-mantra and offer flower garlands, incense and so on. After worshiping the Lord in this way, one should bathe the Lord with milk and dress Him with proper garments, a sacred thread, and ornaments. After offering water to wash the Lord’s feet, one should again worship the Lord with fragrant flowers, incense and other paraphernalia.
Purport:
The dvādaśākṣara-mantra is oṁ namo bhagavate vāsudevāya. While worshiping the Deity, one should ring a bell with his left hand and offer pādya, arghya, vastra, gandha, mālā, ābharaṇa, bhūṣaṇa and so on. In this way, one should bathe the Lord with milk, dress Him and again worship Him with all paraphernalia.