Srimad Bhagavatam — Ashtama Skandha, Shloka 28
Aditi’s Lament and Kaśyapa’s Instruction of the Payo-vrata (Milk Vow) to Please Keśava
निर्वर्तितात्मनियमो देवमर्चेत् समाहित: । अर्चायां स्थण्डिले सूर्ये जले वह्नौ गुरावपि ॥ २८ ॥
nirvartitātma-niyamo devam arcet samāhitaḥ arcāyāṁ sthaṇḍile sūrye jale vahnau gurāv api
その後、日々の霊的規律を果たし、心を統一して主を礼拝せよ。すなわち、御神像において、祭壇において、太陽において、水において、火において、そして霊的師（グル）においても。
FAQs
This verse teaches that after practicing self-discipline, a devotee may worship the Lord with focused mind not only in the Deity, but also by recognizing His presence in sacred manifestations such as the sun, water, and fire.
Because the guru is honored as the Lord’s representative who reveals bhakti and proper worship; therefore, serving and revering the guru is included as a vital limb of devotional practice.
Maintain basic self-discipline, then worship with steady attention—through Deity worship or prayer, and by cultivating reverence for God’s presence in daily essentials (sunlight, water, fire) and by sincerely serving and respecting one’s bona fide spiritual teacher.