The core of one of the explanations offered with regard to this matter is
as follows: As stated in many discourses,1 Gan Eden is granted as a
reward for Torah study, while the Resurrection of the Dead comes as a reward
for the observance of mitzvos. This explains why Gan Eden is a
world of (incorporate) souls, while in the Era of Resurrection, the souls will
be enclothed in bodies. For Torah study relates primarily to the soul, while the
observance of mitzvos relates primarily to the body.2
All Jews observe mitzvos; indeed, “Even the sinners of Israel are as
full of mitzvos as a pomegranate [is full of] seeds.”3 Therefore “Every Jew has a
share in the World to Come.”
It is possible to explain that this is also the intent of the Mishnah’s
citation of the prooftext,4 “And your people are all righteous; they shall inherit the
land forever....” By quoting this verse, the Mishnah, not only brings
proof that all Jews have a share in the World to Come, but also explains why
this is so.
A person who observes mitzvos is referred to as “righteous,” a
tzaddik. {Since all the mitzvos are referred to as
tzedakah,5 “righteousness,” those who perform mitzvos are termed
tzaddikim, “righteous individuals”}.6 Since “your people are all righteous,” i.e., all
Jews, (even the sinners among them) observe mitzvos — moreover they are
“filled with mitzvos,” i.e., the mitzvos they observe fill their
entire existence and being — therefore “they shall inherit the land forever” —
the “Land of Life,”7 which refers to life in the
World to Come.
The above explanation, however, does not account for the Mishnah’s
mention of the conclusion of the verse, “they are the branch of My planting, the
work of My hands, in which to take pride.” [This phrase highlights] the
essential virtue possessed by [all] Jews, that they are “the branch of My
planting, the work of My hands” — (possessing this virtue independent of their
observance of mitzvos).
[By quoting this phrase as part of the prooftext for the concept,] “Every
Jew has a share in the World to Come,” the Mishnah indicates that the
share all Jews possess in the World to Come is (also) a result of their inherent
virtue.