This matter of teachers requires the greatest condition; that is, they should never stain themselves with the world, they should not look for the least pecuniary reward from any soul; nay, rather they should bear the utmost poverty and with the perfect wealth of nature [a state wherein man can dispense with things and be happy in their absence], through the bounty of God, may they associate with the people. They should seek no reward nor recompense. Freely have thy received, freely should they give. His Holiness Christ sayeth: “When ye leave the city, clean off from your shoes the dust thereof.” The holiness of the teachers must reach this degree. Thus may they utter with eloquence, while in ecstasy and great joy, and guide the people to the manifest light.
(‘Abdu’l-Bahá, Tablets of ‘Abdu’l-Bahá v2, p. 359-360)