The secondary creation, which exists by the mercy of the Lord, is the manifest amalgamation of the desires of the living entities. Just as a seed produces additional seeds, activities that promote material desires in the performer produce moving and nonmoving life forms.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
पुरुषानुगृहीतानामेतेषां वासनामयः । विसर्गोऽयं समाहारो बीजाद्बीजं चराचरम्
puruṣānugṛhītānāmeteṣāṃ vāsanāmayaḥ | visargo'yaṃ samāhāro bījādbījaṃ carācaram
SB 12.7.12