Srimad Bhagvata Mahapurana: Book 7: Chapter 14: Verses 35-42
An inquiry into right conduct (continued)
For in that (Rajasuya) sacrifice (performed by you the other day), in the presence even of gods, Rsis (seers) and adepts (in austerity and Yoga etc.) such as Sanaka and his (three) brothers (the mind-born sons of Brahma, the creator), O king, Sri Krsna (the immortal Lord) was recognized as worthy of being adored in the first instance. The great tree in the shape of the egg-shaped universe is crowded with multitudes of Jivas (embodied souls). He being the root of this tree, to worship Sri Krsna (the immortal Lord) is to gratify all living beings as well as one's own self. The (varied) dwellings in the form of (the bodies of) human beings, animals, Rsis (the mind-born sons of Brahma, the creator) and gods have been evolved by Him. He is (known as) the Purusa (the dweller in these habitations) inasmuch as He dwells in these abodes in the form of the embodied soul (and also as their Inner Controller). In these aforementioned bodies, O king, the Lord is present in different degrees (according to the proportion of intelligence, power etc., manifest in them). Hence (because according to this principle, a human soul manifests divinity in a greater degree than the sub-human creation,) a human being (alone) is really deserving of honour. (Even) human beings are worthy of respect more or less in proportion to the degree of self-consciousness manifest in each (individual case).
Perceiving the inclination among the aforesaid human souls to despise one another, O Yudhisthira, the image of Sri Hari was instituted by the wise for worship in Treta and the following Yugas. Thenceforward some people began to worship Sri Hari in images with (various) articles of worship, viewing them with great reverence. Though (reverently) worshipped, an image does not yield the desired result to misanthropes. Even among men, O king of kings, the wise recognize a Brahmana (a member of the priestly class) as eminently worthy of respect. (For) by virtue of (his) asceticism, learning and contentment he preserves the Veda, constituting the body of Sri Hari. Sanctifying the three worlds (heaven, earth and the aerial region) with the (very) dust of their feet, the Brahmanas, O king are indeed worthy of great adoration even in the eyes of Sri Krsna, the Soul of the universe.
Thus ends the fourteenth discourse entitled "An inquiry into right conduct (continued) ",
in Book Seven of the great and glorious Bhagavata-Purana, otherwise known as the Paramahamsa-Samhita.