Avoda Zara 16: Selling Animals to Gentiles, Building With Gentiles

In their wisdom, the rabbis wish to ensure that we do not sell items to Gentiles that might be used as weapons against us.  They discuss the sale of shields, slabs of iron, shovels and axes.  

Will animals sold to Gentiles be used to desecrate Jewish law - or will they be used against Jews, either monetarily or through force?  The rabbis consider whether or not the animals are healthy, whether or not the animals can bear children, and whether or not the animals are suitable for work.

A new Mishna teaches:

• we are not permitted to sell lions, bears or other animals that might cause damage to the public to Gentiles
• we may not build buildings, scaffolds, courthouses (for judging capital cases), or stadiums (where people are thrown in and gored by bulls)
• we are permitted to build altars and bathhouses with Gentiles as long as they are not directly used for idolatry
• we are not permitted to help build any place where an idol will be placed

The Gemara questions which animals can cause damage, which are "lame", the differences between different types and sizes of animals, and which animals work.

Regarding our help with building, we learn that there are three types of buildings used by Gentiles: Kings' buildings, bathhouses, and storehouses.  Are we permitted to build those structures not used by kings?  Or all of these buildings?  Should we be careful to build them without scaffolding, stadiums or storehouses?

Today's daf ends with a story about Rabbi Eliezer.  A baraita teaches that he was seized for teaching Torah, and he was about to serve idolatry.  The officer asked Rabbi Eliezer why he engaged in Torah study, such an idle hobby.  Rabbi Eliezer responded by saying that the true Judge is correct.   The officer thought that Rabbi Eliezer was referring to him.  He said, "since you accepted my words, I promise to free you."  We have to wait until tomorrow learn what happened to him.