Gemara:

Eruvin 

Halacha:

Aveilut,  Eruvin,  Rosh Hashana 

Collections: R' Kleinberg Daf in-Sight: Eiruvin

Description

The nature of Rosh Hashana as a 2 day holiday that is really one long 48-hour period of holiday, applications to the laws of mourning and contrast to yomtov sheini of other holidays