Srimad Bhagavatam — Tritiya Skandha, Shloka 26
Kāla-vibhāga: The Divisions of Time from Atom to Brahmā, and the Lord Beyond Time
एष दैनन्दिन: सर्गो ब्राह्मस्त्रैलोक्यवर्तन: । तिर्यङ्नृपितृदेवानां सम्भवो यत्र कर्मभि: ॥ २६ ॥
eṣa dainan-dinaḥ sargo brāhmas trailokya-vartanaḥ tiryaṅ-nṛ-pitṛ-devānāṁ sambhavo yatra karmabhiḥ
これは梵天の日における日々の創造であり、三界（スヴァルガ・マルティヤ・パーターラ）が巡行する。その中で、獣類・人間・祖霊（ピトリ）・神々は、それぞれの業に応じて現れては消える。
FAQs
It explains that there is a recurring, day-by-day manifestation under Brahmā’s administration, through which the three worlds continue their cycles of activity and population.
This verse states that births across these categories occur according to one’s own karmic actions, which shape the suitable realm and body for experience and consequence.
It encourages mindful, dharmic choices—since actions have shaping power—so one cultivates higher qualities and a trajectory favorable for spiritual progress.