Shavuos is not identified by the Torah with a specific day on the calendar, but as the fiftieth day after the Omer Offering. Each individual is to count every one of the days separately and clearly. Horav Chaim, z.l., m’Volozhin, was wont to say that there is one mussar sefer, book of ethical discourse, that is not “counted” among the many volumes that are available for character development and introspection. It is a simple “sefer,” with a compelling message and readily available – the clock. If a person were to stare at the clock on the wall and watch the seconds tick away into minutes, the minutes tick away into hours, and the hours tick away into days, he will come to realize the value of time and how it is just ticking away – while he sits and watches. This will, hopefully, spur him to wake up and do something about the time that is quickly ticking by.
Horav Zalmen Sorotzkin, z.l., applies Rav Chaim’s analogy to the pasuk in Tehillim 90:12, “Teach us to count our days, that we shall acquire a heart of wisdom.” If we will learn to be aware and count our days, to make sure that they do not go to waste, we will then increase wisdom in our hearts.
The mitzvah of counting days between Pesach and Shavuos as a preparation for receiving the Torah is related to this idea. When one counts a day, he thinks to himself, “Another day has passed on the calendar, another day during which I should have prepared myself for receiving the Torah. Did I do what I was supposed to do – or did I waste another day? What will I now do with the remaining days till Shavuos?” These thoughts will engender a feeling of introspection and sanctity within him, feelings that will bring him closer to being ready to receive the Torah.