Srimad Bhagavatam Canto 02, Chapter 01, Text 37

SB 2.1.37

brahmananam ksatra-bhujo mahatma
vid urur anghri-srita-krsna-varnah
dravyatmakah karma vitana-yogah
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
The virat-purusa’s face is the brahmanas, His arms are the ksatriyas, His thighs are the vaisyas, and the sudras are under the protection of His feet. All the worshipable demigods are also overtaken by Him, and it is the duty of everyone to perform sacrifices with feasible goods to appease the Lord.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
Monotheism is practically suggested here. Offering sacrifices to many demigods under different names is mentioned in the Vedic literatures, but the suggestion made in this verse is that all those varieties of demigods are included in the form of the Supreme Personality of Godhead; they are only the parts and parcels of the original whole. Similarly, the divisions of the orders of human society, namely the brahmanas (the intelligent class), the ksatriyas (the administrators), the vaisyas (the mercantile community) and the sudras (the laborer class), are all included in the body of the Supreme. As such, sacrifice by every one of them in terms of pleasing the Supreme by feasible goods is recommended. Generally, the sacrifice is offered with clarified butter and grains, but with the progress of time, human society has produced varieties of goods by transforming materials supplied by God’s material nature. Human society, therefore, must learn to offer sacrifices not only with clarified butter, but also with other manufactured goods in the propagation of the Lord’s glory, and that will bring about perfection in human society. The intelligent class of men, or brahmanas, may give direction for such sacrifices in consultation with the previous acaryas; the administrators may give all facilities to perform such sacrifices; the vaisya class or mercantile community, who produce such goods, may offer them for sacrifice; and the sudra class may offer their manual labor for the successful termination of such sacrifice. Thus by the cooperation of all classes of human beings, the sacrifice recommended in this age, namely the sacrifice of congregational chanting of the holy name of the Lord, may be executed for the common welfare of all the people of the world.
Srimad Bhagavatam Canto 02, Chapter 01, Text 36
Srimad Bhagavatam Canto 02, Chapter 01, Text 38