Srimad Bhagavatam Canto 11, Chapter 17, Text 19

SB 11.17.19

susrusanam dvija-gavam
 devanam capy amayaya
tatra labdhena santosah
 sudra-prakrtayas tv imah
Service without duplicity to the brahmanas, cows, demigods and other worshipable personalities, and complete satisfaction with whatever income is obtained in such service, are the natural qualities of sudras.
When the entire social order is functioning properly according to Vedic standards, everyone is happy and satisfied. Although the sudras are to be satisfied with whatever income they obtain through their service, they never lack the necessities of life, because the other orders of society, such as ksatriyas and vaisyas, are required to be abundantly generous, and the brahmanas are well known for being the most merciful of all. Therefore, if all social classes obey the Vedic injunctions there will be a new and blissful life for the entire human society under the guidance of Krsna consciousness.
Srimad Bhagavatam Canto 11, Chapter 17, Text 18
Srimad Bhagavatam Canto 11, Chapter 17, Text 20