Gittin 47: Redeeming Captives At Risk; When We Bring First Fruits/Tithes

If a person has been taken captive and is at risk of dying, s/he must be redeemed.  The rabbis walk us through a number of circumstances that are iffy - for example, if a person ate treif food specifically to spite G-d, s/he should not be redeemed (should s/he then be taken captive and will be killed).  But if a person ate treif food because s/he was very hungry, s/he should be redeemed.  

A story is told of Reish Lakish who sold himself as a gladiator.  He brought a rock in a bag with him. His captors asked him for his last wish, and he asked to hit them each one and a half times with the rock.  They complied.  The first captor was killed at once, but Reish Lakish pretended to converse with him so that the others would not flee.  After Reish Lakish retired home, his daughter offered him a pillow to sleep on.  Reish Lakish said that his stomach was his pillow.  We learn later that Reish Lakish wished to leave this life with nothing, and he lamented that he still owned a kav of saffron when he died.

The daf then fully embraces the theme of agriculture.  A new Mishna teaches that when a field is sold to a gentile, the Jewish seller must then bring bikurim, first fruits, to promote tikkun loam, the betterment of the world.   The Gemara discusses the notion that Gentiles can own the earth and what goes under it.  However, the sky until the Heavens belongs to the Jews.  Questions are asked about the nature of the land: when do we consider land to be ownerless?  Should we tithe if a field contains mixed produce?  What if a Jew and a Gentile partner to own a piece of land - do we offer tithes? Does it matter whether land is in Syria or in Eretz Yisrael?  

Deuteronomy 26:11 speaks of the need to rejoice in all that the Lord has brought you and your house.  "Your house" is said to refer to one's wife.  Thus does a husband take his wife's first fruits?  If so, what if she dies while her husband is on route?  For that matter, what should be done if an agent learns that the husband has died while the agent was bringing the first fruits to the Temple?

This change in direction toward agricultural halachot has been a surprise for me.  I'm curious about how this will connect back to the specific questions about Masechet Gittin.