Dakshina meaning and derivation

[Martin Epstein]

I am interested in the word - dakshina -. I have seen it as a direction , south or southern. I have also seen it as donation. What is the connection? Also, are there references to daksina in Upanishads or Veda with regard to donation? I also heard that dakshina is derived from da and ksha. Any info on that?

Thanks for giving these questions your consideration.