Duchening all over the world, except in Eretz Yisrael, Ashkenazim are blessed by the Kohanim only a few times a year: on Rosh Hashanah, Yom Kippur, and on the Yom Tov (but not Chol HaMoed) days of Pesach, Shavuos, and Succos. Sephardim outside Eretz Yisrael do it every day.
In Eretz Yisrael, most Ashkenazim and Sephardim receive all the wonderful blessings of Bircas Kohanim every single day. On Shabbos, Rosh Chodesh, and Yom Tov the Kohanim bless the people twice, once during Shacharis and again at Mussaf, and on Yom Kippur they do so during Ne'ilah as well.
No Peeking!
Don’t try to sneak a peek at the Kohanim during Bircas Kohanim. No one looks at the Kohanim when they are blessing the Jews. Why? Because in the Beis HaMikdash, when the Kohanim gave a berachah to the people, the Shechinah (Hashem’s Presence) rested on the Kohanim’s hands and people were not allowed to see that. Today, we still want to remember the Beis HaMikdash, so we don’t look.
Under the Tallis
What is happening under the Kohen’s tallis? Facing the aron kodesh, the Kohen raises his hands to shoulder height. Palms down, he splits his fingers to make five spaces. After hearing the word “Kohanim,” he begins to make the berachah over the mitzvah of Bircas Kohanim. Halfway through that berachah, all the Kohanim turn around, face the congregation, and complete the blessing. The congregation answers “Amen.” Now the Kohanim are ready to bless the people.
Reprinted from the Parsha Nassa 5785 edition of At the ArtScroll Shabbos Table.