502. Forming the Zimmun

Brachos 5:6

All adult males are obligated in the zimmun as they are in bentching - even the kohanim (priests) who partook of the holiest sacrifices the Temple courtyard. Similarly, kohanim and Yisroelim (Israelites) who ate together are required to recite the zimmun as they are to bentch, even if the kohanim ate terumah (which is forbidden to Israelites) and the Yisroelim ate ordinary food.

Brachos 5:7

Women, servants and minors are not counted in the zimmun but they may form a zimmun among themselves. However, in the interest of modesty, there should not be a zimmun comprising a mixture of women, servants and minors. Instead, women may form their own zimmun, as may servants and minors. These groups do not use God's Name in the zimmun. An androgyne (who has both types of genitals) may make a zimmun with other androgynes but should not form a zimmun with either men or women. A tumtum (whose gender is unclear) should not form a zimmun at all. A minor who understands Who is being blessed in bentching may be counted in a zimmun even if he is only seven or eight years old. He may be counted in both the group of three and the group of ten for a zimmun. A non-Jew cannot be counted in a zimmun.