We see the importance of the number seven in Parshat Behar, Vayikra 25:8-10:

You shall count for yourself seven shmita (sabbatical) years, seven years, seven times and it shall be for you, the days (period) of the seven sabbatical years, forty-nine years. You shall make a proclamation with the shofar on the tenth day of the seventh month. On Yom Kippur shall this shofar-proclamation be made throughout all your land. You shall sanctify the year of the fiftieth year and proclaim freedom in the land for all its inhabitants; it shall be for you a Yovel, jubilee and each man shall return to his ancestral land and each man shall return to his family.

This sounds similar to Sefirat HaOmer, the countdown of the days between Pesach and Shavuot which we read about last week in Vayikra 23:15-16:

You shall count for yourselves, from the day after the day of rest (Pesach) from the day on which you will bring the omer wave-offering, seven complete weeks they shall be. Until the day after the seventh week, you shall count fifty days and you shall bring a new meal offering to God.

In both cases we are counting seven groups of seven. During the Yovel year the shofar is blown just as it was blown at Mt. Sinai when B’nei Yisrael received the Torah.

This Tuesday evening, we will also be blowing the shofar as we do every year on Yom Yerushalayim, celebrating the Yovel, the jubilee year of the liberation and reunification of Jerusalem. There will be many special observances and festivities in Jerusalem including a ceremony that will take place along the walls of the old city depicting the history of Jerusalem from Biblical times until today. In addition there will be many concerts and prayer services with live music throughout the city. Tourists from around the world will be flying in to Jerusalem to celebrate this historic jubilee year.

In Vayikra Raba 29 we learn that all the sevenths are favorites:

Of the days, the seventh is a favorite, as it is written (Breisheet 2:3) “And God blessed the seventh day and sanctified it: because in it He rested from all His work which God created and performed.”

Of all of the months the seventh is a favorite, as it is written (Vayikra 23:24) “In the seventh month, on the first day of the month, shall you have a shabbaton, a memorial of blowing of horns, a holy gathering (Rosh HaShana).”

Of the years the seventh is a favorite as it is written (Shmot 23:11). “And six years you shall sow your land and gather in its fruits: But in the Seventh Year you shall let it rest and lie fallow that the poor of your people shall eat…”

Of the shmitot (sabbatical years) the seventh is favorite as it is written (Vayikra 25:10), “And you shall hallow the fiftieth year.”

As we enter Shabbat, the seventh day of the week, in the midst of our counting the 49 days of the omer and in anticipation of the 50th Yom Yerushalayim, may we be blessed with the opportunity to continue counting the days to more happy occasions for many more years.