1. Rav Chisda relates three pairs of words whose meanings were exchanged after the destruction of the Beis ha'Mikdash.
2. Abaye and Rav Ashi each added another pair of words that exchanged meanings after the destruction of the Beis ha'Mikdash.
3. The Mishnah discusses the issue of placing a pot of uncooked food on the fire before Shabbos and leaving it there during Shabbos.
4. There is a dispute about what may be placed before Shabbos in a place where coals were taken away or covered with ash.
5. There is a dispute about whether food may be returned to a place where coals were removed or covered with ash on Shabbos.
A BIT MORE
1. For example, a Shofar used on Rosh Hashanah started to be called a "Chatzotzrah" after the destruction, and the Chatzotzrah started to be called a "Shofar." Accordingly, if an unlearned person asks what he should use as the Shofar on Rosh Hashanah, he is told to use a Chatzotzrah.
2. Abaye: The words "Huvlila" and "Bei Kasi" were exchanged (which makes a difference in the laws of Tereifos). Rav Ashi: The words "Bavel" and "Bursif" were exchanged (which makes a difference in the laws of what witnesses must say when they bring a Get to a Beis Din).
3. When the fuel is coals or wood (as opposed to straw), it is prohibited. There is a possibility that a person might stoke the coals or wood to cause his food to be ready sooner. If one removes the coals or covers them with ash before Shabbos, it is permitted.
4. Beis Shamai: One may put only hot boiled water there, but not cooked food. Beis Hillel: One may put both hot water and cooked food on such a fire.
5. Beis Shamai: If the food was placed on this area before Shabbos, one may take it off on Shabbos but may not return it.
Beis Hillel: Under certain conditions one is permitted even to return it.