Mitzvah 281-282) That the live-in worker of a priest, his hired worker and an uncircumcised person may not eat Terumah
“A tenant of a priest, or a hired servant, may not eat of the holy thing!” (Vayikra 22:10)
It is a negative commandment that the tenant of a priest (who is permanently rented to him), and a hired servant (a worker who is hired temporarily), may not partake of the Terumah, as it says “A tenant of a priest, or a hired servant, may not eat of the holy thing!”.
The root of this commandment and all of its subject is included in the previous commandment of a non-priest eating Terumah, and since these people do not actually belong to the priest, they are considered like non-priests.
It is also a negative commandment that an uncircumcised person may not eat Terumah, even if he is a priest. This is true whether he deliberately did not circumcise himself and whether it was by accident, or even if he is unable to be circumcised (for example if his brothers died as a result of the circumcision and he is not allowed to be circumcised because of the worry that he will also die), nevertheless because he is uncircumcised he may not eat Terumah or any other holy food. This law is not explicit in the verse, but is derived from a gezerah shavah (a method of derivation using identical words which appear in two places and comparing the relevant laws).
Amongst the roots of the commandment are that an uncircumcised person is considered like a non-priest, since he has not entered into the covenant of circumcision (which is a very important thing) with the rest of Klal Yisrael, and the keeping of non-priests and impure people from Terumah and holy things all have one root as has already been explained.
This commandment applies to priest, wherever there is biblical Terumah, as we have explained in the previous commandment.