The land was to be divided by lot among the families of the Israelites when the possession of it was obtained. Num 26:52-56; Num 33:54, etc. At the end of every seventh sabbatical cycle of years, in the year of Jubilee, each field or estate that might have been alienated was to be restored to the family to which it had been originally allotted.
Lev 25:8
Seven sabbaths of years - seven weeks of years.
Lev 25:9
Cause the trumpet of the jubile to sound - Rather, cause the sound of the cornet to go through (the land). The word jubile does not occur in this verse in the Hebrew. The trumpet is the shofar שׁפר shôphār, i. e. the cornet (rendered “shawm” in the Prayer-Book version of Psa 98:7), either the horn of some animal or a tube of metal shaped like one. As the sound of the cornet (see Lev 25:10 note) was the signal of the descent of Yahweh when He came down upon Sinai to take Israel into covenant with Himself Exo 19:13, Exo 19:16, Exo 19:19; Exo 20:18, so the same sound announced, at the close of the great day of atonement, after the Evening sacrifice, the year which restored each Israelite to the freedom and the blessings of the covenant.
Lev 25:10
The fiftieth year - The Jubilee probably coincided with each seventh sabbatical year, and was called the fiftieth, as being the last of a series of which the first was the preceding Jubilee.
A jubile - Commonly spelled jubilee. The original word first occurs in Exo 19:13, where it is rendered “trumpet,” margin “cornet.” It most probably denotes the sound of the cornet, not the cornet itself, and is derived from a root, signifying to flow abundantly, which by a familiar metaphor might be applied to sound.