By Rabbi Shlomo Zargari:
Shalom,
We are in the midst of the days of Sefirat Haomer. If we pay attention we can see that these days create one unit of time which begins with Pesah and ends with Shavuot. This shows a very meaningful connection between the two.
Pesah is not completed until Shavuot, says Harav Aharon Kotler זצ״ל: Pesah is the holiday of redemption, however this redemption is not perfect so long as we have not accepted the Torah,
״אין לך בן חורין אלא מי שעוסק בתורה״
A free person is one who delves in Torah.
Without Torah, it’s a temporary freedom, because it can be taken away in a blink of an eye, as it happened throughout our long history, we have witnessed our political freedom was taken away time and again.
With the acceptance of the Torah however, we accepted the true everlasting spiritual freedom. The Ramban writes that the days of Omer are similar to days of Hol Hamoed, Shavuot is the last days of the holidays: “ … He commanded on the holiday of the Masot seven days with sanctity before and after them, to show that they’re all holy, and the Shechina is present.
And from then was added 49 days and ended with Shavuot which is similar to the eighth day of Sukkot, and the ( in between days) that we count are like Hol Hamoed, between the first and last days, and that’s the day of the giving of the Torah when they heard the word of HaShem through the fire, and that’s why our sages call this day “ עצרת” because it’s similar to the last day of Sukkot with the same name given to it in the Torah! (Ramban Parashat Emor 23,36)