story identification - Book about two alien castes, alien hand modification

I remember reading a book in high school where a group of people travel to an alien planet where they discover an alien civilization separated into 2 castes. they are then made slaves to the taller class of aliens and one man has the flesh removed from his hands to make his fingers appear longer.

Answer

This novel, by Mary Doria Russell, features a Jesuit priest who goes to an alien planet, and is severely disillusioned by what he finds there.

The title, of course, is a Biblical reference:

Are not five sparrows sold for two farthings¹, and not one of them is forgotten before God?

_{^{Luke 12-6, KJV}}

There are two alien “castes,” but they’re really different species, one of which preys on the other:

When the Earthlings meet a member of the culture which produced the radio transmissions, he proves to be of a different species from the rural natives, a Jana’ata. An ambitious merchant named Supaari VaGayjur sees in the visitors a possibility to improve his status, while the crew hopes to find an alternative source of fuel in Supaari’s city, Gayjur. Meanwhile, the crew begins to grow their own food, introducing the concept of agriculture to the villagers. These seemingly innocent actions and accompanying cultural misunderstandings precipitate events which lead to a slaughter. Though not closely related, the Jana’ata have evolved by aggressive mimicry to physically resemble the Runa, who are in fact their prey species. The human intervention leads to a Runa baby boom which is harvested by the predatory Jana’ata.

Among other things, the priest is subject to some unwelcome disfiguration:

Sandoz becomes a slave/pet of a famed poet-songwriter, whose broadcasts first alerted Earth to Rakhat’s existence. Sandoz is physically disfigured. In that culture, it is considered an honour to be dependent upon another, and likewise to have a dependent, a mutilation analogous to the practice of foot binding. The flesh between Sandoz’s metacarpal bones is cut away to make it seem that he has long elegant fingers like the hasta’akala plant (which grows on a stronger tree and is thus dependent). The disfiguration starts at Sandoz’ wrists, and with which he cannot even feed himself.

It has received many award, and been adapted to television

_{1: Actually an as.}