Basically, these verses indicate that the Jubilee requires all debts between Jews to be annulled. Also, any Jew that sold his or herself into slavery is released, whether they worked the amount of time they promised, or not. Rashi, (11th century France) points out the world Jubilee is related to the Hebrew word for "ram," alluding to the fact that the Jubilee year is proclaimed by the blast of a ram's horn! Nachmanides adds that the word Jubilee is also related to the Hebrew word which means "to move around." Thusly, we are reminded that all Jews who had sold themselves into slavery, or were shackled (so to speak) by debt, were now released from their bonds and were given the freedom TO MOVE AROUND.
The origination of the counting didn't actually start at the time the Jews entered into the Land of Israel, but rather after they finished conquering the Land and after apportioning it to each family, which was 1288 BCE. (source: Maimonides - Laws of Shmita and Jubilee 10:2) The first Jubilee was forty-nine years later. The Sanhedrin was in charge of counting the years and ensuring its accuracy. The nation was notified of the Jubilee year's arrival by the blast of the shofar at the end of Yom Kippur. (Leviticus 25:8 and Numbers 35:4)
However, the Jubilee year is only celebrated when the majority of Jewish people live in the land of Israel, and since there are so many Jews still in exile, the Jubilee year is not celebrated. Furthermore, since the Holy Temple has been destroyed and the great Sanhedrin dissolved, we have suspended calculating the Jubilee year.
However, we still blow the Shofar every year after Yom Kippur, even in our times. Why? Because the blow of the Shofar still tells us that we can still be released from our bondage -- the bondage of habitual mistakes.
When a person is careless, and he lets himself repeatedly make the same mistake, he becomes habituated to constantly make that mistake. So to speak, he becomes enslaved to habit. Imagine the cigarette smoker. The first cigarette is a purposeful blunder on the smoker's part. So too is the second cigarette, maybe even the first pack. But when a person becomes addicted to cigarettes, the cigarette becomes the master, and he becomes their slave.
On Yom Kippur, we strive to gain control over our habits -- symbolized by refraining that day from food and drink. Then, when the Shofar blows at the end of Yom Kippur, it is as if to announce, "All those who were enslaved (to their habits) are now free men!"
With blessings from Jerusalem,
Rabbi Shraga Simmons