A Commentary, Critical, Practical, and Explanatory on the Old and New Testaments, by Robert Jamieson, A.R. Fausset and David Brown  at sacred-texts.com
lev 25:2SABBATH OF THE SEVENTH YEAR. (Lev 25:1-7)
When ye come into the land which I give you--It has been questioned on what year, after the occupation of Canaan, the sabbatic year began to be observed. Some think it was the seventh year after their entrance. But others, considering that as the first six years were spent in the conquest and division of the land (Jos 5:12), and that the sabbatical year was to be observed after six years of agriculture, maintain that the observance did not commence till the fourteenth year.
the land keep a sabbath unto the Lord--This was a very peculiar arrangement. Not only all agricultural processes were to be intermitted every seventh year, but the cultivators had no right to the soil. It lay entirely fallow, and its spontaneous produce was the common property of the poor and the stranger, the cattle and game. This year of rest was to invigorate the productive powers of the land, as the weekly Sabbath was a refreshment to men and cattle. It commenced immediately after the feast of ingathering, and it was calculated to teach the people, in a remarkable manner, the reality of the presence and providential power of God.
lev 25:8THE JUBILEE. (Lev. 25:8-23)
thou shalt number seven sabbaths of years--This most extraordinary of all civil institutions, which received the name of "Jubilee" from a Hebrew word signifying a musical instrument, a horn or trumpet, began on the tenth day of the seventh month, or the great day of atonement, when, by order of the public authorities, the sound of trumpets proclaimed the beginning of the universal redemption. All prisoners and captives obtained their liberties, slaves were declared free, and debtors were absolved. The land, as on the sabbatic year, was neither sowed nor reaped, but allowed to enjoy with its inhabitants a sabbath of repose; and its natural produce was the common property of all. Moreover, every inheritance throughout the land of Judea was restored to its original owner.
lev 25:10ye shall hallow the fiftieth year--Much difference of opinion exists as to whether the jubilee was observed on the forty-ninth, or, in round numbers, it is called the fiftieth. The prevailing opinion, both in ancient and modern times, has been in favor of the latter.
lev 25:12ye shall eat the increase thereof out of the field, &c.--All that the ground yielded spontaneously during that period might be eaten for their necessary subsistence, but no persons were at liberty to hoard or form a private stock in reserve.
lev 25:13ye shall return every man unto his possession, &c.--Inheritances, from whatever cause, and how frequently soever they had been alienated, came back into the hands of the original proprietors. This law of entail, by which the right heir could never be excluded, was a provision of great wisdom for preserving families and tribes perfectly distinct, and their genealogies faithfully recorded, in order that all might have evidence to establish their right to the ancestral property. Hence the tribe and family of Christ were readily discovered at his birth.
lev 25:17Ye shall not oppress one another, but thou shalt fear thy God--This, which is the same as Lev 25:14, related to the sale or purchase of possessions and the duty of paying an honest and equitable regard, on both sides, to the limited period during which the bargain could stand. The object of the legislator was, as far as possible, to maintain the original order of families, and an equality of condition among the people.
lev 25:21I will command my blessing upon you in the sixth year, and it shall bring forth fruit for three years, &c.--A provision was made, by the special interposition of God, to supply the deficiency of food which would otherwise have resulted from the suspension of all labor during the sabbatic year. The sixth year was to yield a miraculous supply for three continuous years. And the remark is applicable to the year of Jubilee as well as the sabbatic year. (See allusions to this extraordinary provision in Kg2 19:29; Isa 37:30). None but a legislator who was conscious of acting under divine authority would have staked his character on so singular an enactment as that of the sabbatic year; and none but a people who had witnessed the fulfilment of the divine promise would have been induced to suspend their agricultural preparations on a recurrence of a periodical Jubilee.
lev 25:23The land shall not be sold for ever--or, "be quite cut off," as the Margin better renders it. The land was God's, and, in prosecution of an important design, He gave it to the people of His choice, dividing it among their tribes and families--who, however, held it of Him merely as tenants-at-will and had no right or power of disposing of it to strangers. In necessitous circumstances, individuals might effect a temporary sale. But they possessed the right of redeeming it, at any time, on payment of an adequate compensation to the present holder; and by the enactments of the Jubilee they recovered it free--so that the land was rendered inalienable. (See an exception to this law, Lev 27:20).
lev 25:29if a man sell a dwelling house in a walled city, then he may redeem it within a whole year after it is sold--All sales of houses were subject to the same condition. But there was a difference between the houses of villages (which, being connected with agriculture, were treated as parts of the land) and houses possessed by trading people or foreigners in walled towns, which could only be redeemed within the year after the sale; if not then redeemed, these did not revert to the former owner at the Jubilee.
lev 25:32Notwithstanding the cities of the Levites, &c.--The Levites, having no possessions but their towns and their houses, the law conferred on them the same privileges that were granted to the lands of the other Israelites. A certain portion of the lands surrounding the Levitical cities was appropriated to them for the pasturage of their cattle and flocks (Num 35:4-5). This was a permanent endowment for the support of the ministry and could not be alienated for any time. The Levites, however, were at liberty to make exchanges among themselves; and a priest might sell his house, garden, and right of pasture to another priest, but not to an Israelite of another tribe (Jer 41:7-9).
lev 25:35if thy brother be waxen poor, . . . relieve him--This was a most benevolent provision for the poor and unfortunate, designed to aid them or alleviate the evils of their condition. Whether a native Israelite or a mere sojourner, his richer neighbor was required to give him food, lodging, and a supply of money without usury. Usury was severely condemned (Psa 15:5; Eze 18:8, Eze 18:17), but the prohibition cannot be considered as applicable to the modern practice of men in business, borrowing and lending at legal rates of interest.
lev 25:39if thy brother . . . be waxen poor, and be sold unto thee, thou shalt not compel him to serve as a bond-servant--An Israelite might be compelled, through misfortune, not only to mortgage his inheritance, but himself. In the event of his being reduced to this distress, he was to be treated not as a slave, but a hired servant whose engagement was temporary, and who might, through the friendly aid of a relative, be redeemed at any time before the Jubilee. The ransom money was determined on a most equitable principle. Taking account of the number of years from the proposal to redeem and the Jubilee, of the current wages of labor for that time, and multiplying the remaining years by that sum, the amount was to be paid to the master for his redemption. But if no such friendly interposition was made for a Hebrew slave, he continued in servitude till the year of Jubilee, when, as a matter of course, he regained his liberty, as well as his inheritance. Viewed in the various aspects in which it is presented in this chapter, the Jubilee was an admirable institution, and subservient in an eminent degree to uphold the interests of religion, social order, and freedom among the Israelites.