With the conclusion of the first day of Pesach, we begin the mitzvah of counting the Omer:
And you shall count for yourselves from the morrow after the day of rest, from the day of your bringing the sheaf of the waving, seven complete weeks there shall be. Until the morrow of the seventh day of rest, you shall count fifty days.
From the second day of Pesach until the holiday of Shavuos, we fulfill this commandment each day. Men who attend the synagogue to recite the evening Maariv service conclude their prayers with a blessing and then declare: "Today is so-and-so many days, which are so-and-so many weeks, and so-and-so many days, to the counting of the Omer."
By counting the Omer, we stress the connection between Pesach, when we gained our physical freedom and the spiritual goals our freedom allows us to pursue.
How so? Our ancestors left Egypt after more than one hundred years of servitude. Immediately, the very day after their exit from the house of Bondage, they are called upon to stop and consider the purpose of their new-found freedom:
"Not so fast, there. This is not the time to sit back on your laurels and enjoy a good rest. The goal of the Exodus has not yet been attained. You have just started out on your spiritual journey to Mount Sinai; your release from physical bondage is only the beginning.
"Continue on your route to receive the Torah, G-d's 'constitution' for your newly-created nation. Thus you will gain true freedom, not only in the physical sense, but in a spiritual dimension as well."
Sefiras HaOmer counts each of the fifty days between Pesach – time of the Exodus from physical enslavement -- and Shavuos, when we became G-d's nation by accepting His Torah at Sinai. Thus it demonstrates the clear connection between the two.
We repeat it each year to avoid the pitfall of viewing our liberation from a foreign yoke as the most momentous accomplishment in its history. Each of the fifty days, as we declare how many days have gone by in our "climb" from Egypt to Sinai, we again renew our determination to gain the maximum. Physical liberty is not enough on its own; to have permanent value, it must be combined with spiritual freedom, that we be free to obey the moral dictates of our conscience and serve G-d as an independent nation.
This moral freedom and purity which characterized the Jewish nation from its very founding. Only by fulfilling our national destiny can we achieve happiness and satisfaction.
In the generation of the Exodus, each passing day of the Omer brought the former slaves that much nearer to their goal of becoming G-d's chosen nation.
And so, too, today: Each additional day we count brings us closer to the meeting at the foot of Mount Sinai, when we received G-d's Torah and became His holy People.
A prisoner nearing the day of his release counts the days eagerly. So, too, did the Jewish people in the desert keep a reckoning of the days that remained. In this sense, Pesach was the harbinger of Shavuos, that momentous day when they would be privileged to serve their Creator and receive His Torah at Sinai.
Sefiras HaOmer, the counting of the Omer, teaches us not to separate physical liberty from moral freedom. Without the events at Sinai, our release from Egypt loses its eternal significance. Political freedom becomes endangered if viewed as an end in itself rather than a means to achieving morality. Many national revolutions succeeded in achieving political freedom, only to lead to degeneracy because their leaders thought that their task had been completed when the yoke of foreigners was cast off successfully. They failed to free the spirit of their countrymen and to direct it towards spiritual channels. Consequently, their battles to free their people, at the cost of countless lives, achieved no permanent good. There was no moral vision, no ideals set before the newly-freed combatants when they assumed their rightful place among the family of free nations.
The Torah guides us to avoiding this pitfall by commanding us to count these forty-nine days. Thus we declare anew each year that the Exodus from Egypt was only the first step. True, it was an essential stage in our progress, but it was only the beginning. Its significance was realized only fifty days later, at Sinai, when we completed our climb up the ladder of spiritual achievement.
It is the successful completion of this process of growth of the spirit which embodies the true crown of liberty, both for the individual, and for the entire nation, yet today.
-- Adapted from Parasha Velikchah, by Rabbi Moshe Grylak