The kabbalists posed a problem that sounds simple until you sit with it: no one is truly perfect unless he has observed all 613 mitzvot. And yet — who has ever done so?
Not even Moses. The master of the prophets, peace be upon him, did not keep them all. The reason is not moral. It is structural.
Four obstacles, the sages said, prevent any single person from observing every commandment.
First, the obstacle of category. Priestly laws bind only the Kohanim. Levitical duties fall only on Levites. Certain Israelite laws exclude both. A priest cannot perform the mitzvot of a non-priest. A non-priest cannot perform the mitzvot of a priest. The Torah distributes commandments the way a family distributes inheritance — some to each child, none to all.
Second, the obstacle of circumstance. The commandment to circumcise a son cannot be performed by a man without a son. Many mitzvot depend on life situations that never arise.
Third and fourth, the obstacles of condition and exception. Many commandments apply only to the Temple, many only in the Land of Israel. Without Temple or Land, whole tractates of obligation fall dormant, waiting for restoration.
The teaching is humbling and liberating. Jewish perfection is not an individual score. It is communal arithmetic. No Jew keeps all 613 — but the Jewish people, taken together across priest and Levite and Israelite, male and female, Land and diaspora, keeps them all. The covenant is a team assignment.