When G‑d told Moshe to relay various mitzvos to the Jewish people, He used the expressions: “speak to the children of Israel,” “say to the children of Israel” or “command the children of Israel.”1

All commandments, even those conveyed with the expressions “speak” or “say,” are termed mitzvos , rooted in the word tzavei — “command.” Thus, all are considered commands and decrees. Nevertheless, the use of the expression “command” concerning specific mitzvos indicates that the idea of command plays a larger role with these than it does with mitzvos introduced with the terms “speak” or “say.”

This is why our Sages state in Toras Kohanim , at the beginning of the Torah portion of Tzav (“Command”), that “command” indicates an “urging on with alacrity, both now as well as for coming generations.”

Chassidus explains2 that the word mitzvah — commandment — derives from the expression tzavsa v’chibur, “cleaving and attachment,” for the underlying purpose of all mitzvos is that through them one becomes bound and “attached” to G‑d.

We thus understand that although binding and attachment applies to all mitzvos , a greater degree of attachment is achieved through those mitzvos relayed to us with the expression “tzav — command,” for this expression more clearly indicates attachment.

The difference between “speak,” “say,” and “command” is that when one is merely spoken to, or is merely told to do something, he is entirely free to do as he wishes. This is not the case when one is commanded to do something. The issuing of a command presupposes that the one doing the commanding has some degree of dominance over the individual being commanded. For example, an army officer can command a subordinate; he cannot issue commands to one of the same rank as himself — he can “speak” to him, but cannot “command” him.

Thus, a person is less free to ignore mitzvos conveyed with the term “command” than he is to ignore those relayed with the words “speak” or “say”; in the former instance, it is as if the person were coerced to obey.

Accordingly, “speak” and “say” mitzvos — obedience to which is left up to the hearer — accomplish most of their “cleaving and attachment” when a Jew actually fulfills them.

Not so with mitzvos conveyed with the word “command”: Since there is a greater certainty that the person will fulfill them, their “cleaving and attachment” is fully accomplished at the moment the command is issued.

While “command” mitzvos achieve “cleaving and attachment” at an earlier stage than do other mitzvos , all mitzvos accomplish this sooner or later. How so?

The previous Lubavitcher Rebbe offers the following parable:3 An intellectual giant whose whole life revolves around knowledge will ignore a person who has nothing to do with matters of intellect — the simpleton is not negated; he simply does not exist in the genius’s world. The simpleton, too, will feel himself to be nonexistent in comparison to the prodigy.

However, when the wise man commands the simple one to do something for him, suddenly the simple person exists to the wise man. As well, the simple person becomes aware of his own importance.

Based on Likkutei Sichos Vol. VII pp. 30-34.