Though they both speak about korbanot, sacrifices, there is a sharp distinction between last week’s Torah reading, Vayikra, and this week’s Tzav. Rashi explains that the word Vayikra is a term of endearment, as evidenced by the fact that the angels use it when they begin their praises of G-d, as it says “Vayikra Ze El Ze”, “They called one to another” (Yishayah 6: 3. We also recite the phrase daily in the Kedushaprayer, imitating the angels’ praise of G-d). On the other hand, “Tzav” means “command”, and carries with it connotations of inducing and encouraging someone to perform an action that they are not keen to do.
The portion of Vayikra contains instructions to the Jewish people as to how to bring the sacrifices. The Hebrew word “Korban” is closely related to the word “Kiruv”, “closeness”. This is because the purpose of any sacrifice is to draw close to G-d. The two main types of sacrifice are those which are brought to attain atonement for an inadvertent sin, and a voluntary offering thanking and recognising the good that G-d has performed for us. Both of these bring us closer to G-d. Atonement breaks down the barriers of sin with which we have surrounded ourselves, strengthening our relationship with our Creator. Voluntary offerings are our way of showing our total dependence upon G-d, and that He is the source of all our success and prosperity.
Rav Dessler explains that the way to foster love towards someone is to give to them. The classic proof of this is our children. When they are born they are total takers, incapable of returning even a smile by way of thanks. But this enables the parents to give totally to their children, and thus foster a close bond of love. Stories of children separated from their parents show that the relationship is weakened if the parents have not had the opportunity to give and to look after their children. Similarly, G-d in His mercy commanded us to bring sacrifices to Him. Though by definition He lacks nothing, through the sacrifices He gave us an opportunity to ‘give’ to Him as a means of fostering love and closeness.
Therefore G-d calls to Moshe, and instructs him to tell the people about sacrifices using a term of endearment. The concept and purpose of sacrifices can only be achieved through a desire to draw close and express affection.
The portion of Tzav however contains primarily instructions for the Cohanim as to how they should perform the sacrifices. They do not gain personally from offering the sacrifices. In fact they lose their own identity. The Talmud explains that Cohanim perform a dual function, they are emissaries of G-d when they bless the people, and they are messengers of the people when they offer the sacrifices. They are merely performing actions on behalf of others, but do not benefit personally from the sacrifices which they offer.
Therefore G-d instructs Moshe to “command” them about the sacrifices. Rashi adds, “Rabbi Shimon says, the Torah especially needs words of encouragement where there is a monetary loss involved”. At first glance this seems backwards; the Cohanim are not losing out financially by offering the sacrifices. It would have seemed more appropriate to place this command at the beginning of Vayikra before commanding the people to spend their money buying animals for sacrifices. But having looked deeper, we can see that any amount of money is worth paying in order to bring a sacrifice. Who can put a price on drawing close to G-d, and who would not willingly pay whatever that costs. On the other hand, the Cohanim are merely acting on behalf of another. They do not gain anything personally from their hard work, but spend all day working for others. It does not cost them directly, but they are not gaining from their time spent working. It must be tempting for them to give up their role as priests and go out to get a paying job like everyone else. Therefore G-d needs to give them an extra push of encouragement by using the word “Tzav” to get them to perform their tasks.