As a safeguard to the prohibition of priests offering sacrifices while intoxicated, our Sages forbade the priests scheduled to serve in the Temple on a particular day from drinking wine that day. Moreover, our Rabbis maintain that even after the destruction of the Temple, this prohibition is relevant. For at any moment the Temple may be rebuilt and the priests will be called upon to perform their sacrificial service. Accordingly, they argue, it would be appropriate to forbid priests from drinking wine at any time, for at any moment, Moshiach may come and cause the Temple to descend from heaven. Thus they might be intoxicated when they are called on to serve in the Temple.
Ultimately, the halachah does not follow this argument. But the fact that there is such an argument communicates an important message. Our Sages did not consider Moshiach’s coming and the rebuilding of the Temple as an abstract wish of the far-off future, but a real factor, affecting their lives in the here and now. They understood Moshiach in the present tense and were willing to consider making decisions in Torah Law that reflect the immediate possibility of his coming.