His chief ethical work, Mesillat Yesharim, is still widely read today. His many Hebrew writings make him one of the fathers of modern Hebrew literature. The use of both forms led to much commentary in the Talmud and Midrash. Thus the combination of binyan and imperative express 'immediacy'. The Talmud explains that the priests might be a little lax and tardy in observance of the daily burnt-offering because of a monetary loss involved.
Opinions differ on the exact nature of that loss.
The application of the mitzvah for future generations is derived from other places where the word tzav is followed by immediate fulfillment. In contrast to the sacrifices mentioned in the previous chapters of Yayikra, the use of tzav here is that the daily burnt offering is compulsory unlike the other previous sacrifices which were offered as the occasion demanded. The Talmud Yerushalmi gives the following aid to remember this. The Torah first mentions the Mitzvah and then 'speak to the Israelites'. This will enable him to participate in the Pesach sacrifice.