In celebration of 100 episodes of Responsa Radio, we're re-releasing our favorites with an update from Rav Eitan and Rav Avi at the end of the episode.

Our producer, Jeremy Tabick's favorite is episode #7: The laws of eruv—constructing a sometimes questionable boundary around a neighborhood to allow carrying objects on shabbat—often seem obscure, bizarre, and made-up. But what are the ways in which it makes sense? What are the operating principles behind these laws?