Gemara:

Sotah 

Halacha:

Birchas Kohanim,  Tefillah 

Collections: R' Grunstein Duchening

References: Sotah: 38B  

Description

Is Duchening OUTSIDE the Temple, without the sacrafices done prior, a Biblical commandment, or just rabbinic? Perhaps this would explain limiting it to Yom Tov only