The problem we have is in trying to fit our understanding of possession within the framework of God's original plan.
When God said 'possess the land' the concept involved stewardship and use, not taking title. Why? Because God owned the title and all the land was His. It was his to 'give' to whom he would. Recognizing the land as His property, was a recognition of his authority, our responsibility and accountablity. But since the early rebellion in the garden, man sought to establish his own authority and possession. When God covenanted with Abraham over the land that was to become Israel, it was a totally different time and understanding.
In some parts of the world, land was 'possessed' by the powerful: Those rich enough to occupy, or cunning enough to take the property from others laid claim to the land and the concept of property ownership developed. Before that time land was occupied and used by families and tribes according to their means of occupation and utilization. Jealousies rose, along with control and greed when a person had (for example) herds requiring water as well as grazing lands, and another saw the that controlling access to the water would hinder the economy and growth of a neighbor and thus give them advantage or control of a neighbor; they might use their cunning or warfare to limit access to wells, and bodies of water.....or demand a price of those in need. Eventually, land came to be valued not for its contribution to the existance of man, but as a potential of its use... and the control of anothers wealth by taking control and limiting or prohibiting access.
Man's form of life and society moved from a tribal herdsman, to a more settled agrarian life and community. Some saw the pillage of tribal warfare decimate these small groups and formed alliances with others and formed cities where human kind was more concentrated and where the interest of marketing and business was done: As such, these concentrated groups developed a system of perceived wealth and strength, and they also found themselves subject to the attack and pillage by others and so planned for their own defense and security.
The most wealthy and powerful developed a system of overlords and by promising 'security' and 'defense' or protections in times of famine, or pricing, could controll and/ or limit the access to needed provisions, thereby gradually gaining more and more power over those who used the land.
Through a willingness to trade security for fear, or to accept promises and protection against risks both natural and man made, those of lesser or weaker means started giving in to those which had more: At first it might be a fee or a tax. The strong got stronger as the weak got weaker. Those making a living off the land, had a means by which to provide food for their families and work for their families and their children. But as they caved in to the need for protection, a source for equipment, specialty goods, and provisions which required business and travel, they depended on those who did not directly live off the land... They could use their harvest and their crafting skills to produce products to barter with. But they could not provide everything they needed, particularly developing 'technology' which would add to their comfort and productivity. But the one in possession of these 'necessities' could drive the price according to need: If the buyer wasn't willing to pay the price, the seller developed the 'art form' of increasing the price and the perceived value and necessity, also of manipulating the environment or the conditions which would eventually coerc the buyer to pay the price demanded: When a 'credit' for goods or services was extended, the buyer was asked to put up a guarantor: it might be a person for servatude or the use of a portion of the land on which he depended, especially if the harvest failed or a glut occurred to devalue the harvest.
Once the land was used as a guarantee for a price owed, the use of that land went from the buyer to the seller until the price was paid. If the buyer was still allowed to use the land then his labor was without wages and the product of the land became the sellers' . Once a person was so indebted to the wealthy merchant/lords/ protectors so that he had lost the income and livelihood off the land, and control and use of the land, he became a servant to those who claimed those rights and could be manipulated by permissions to use or restrictions for use.
But God set forth laws regarding the land, and it was proportioned by God to the tribes of Israel for an inheritance, not to be subject to a perpetual sale; If a person or a family found themselves in so much need, for whatever reason, that they must offer their freedom to use the land as they saw fit, to another.....then that is what happened. If they were unable to pay back their debt, then the control of choice in use of the land continued with the lender until the debt was paid.
In the righteousness of God, a kinsman, so seeing his brother in need, and having pity or compassion or seeing his duty as a relation, could offer the price of the debt and return the use back to the debtor as a debt forgiven...... the kinsman redeemer. Not all were willing to exercise this God honoring practice of kin-relationship and part with their wealth to a family member who was unfortunate to fall into poverty, perhaps due to sickness or lack of productive skills.
In his wisdom and his determination that the inheritance would remain as he had ordered it, God set forth laws which prevented the acquiring of permanent lands by those who were more powerful, stronger, and/or wealthy and cunning over those who had less: For one thing, their lending was to be without usery or interest/fees. For another, their taking possession or control over a property on which another's life depended, was limited and they were not allowed to deprive the debtor of the necessities of living; Futhermore, whether near or far, when the year of jubilee came, whether a debt was paid or not, the lender was to return that which had been held as a garantee....if it was a person or control of his land, and the unpaid debt forgiven.
In addition, the ownership of all the land by God was acknowledge in the obediance to allowing the land to rest every 7 years. This rule, not only acknowledged and honored God and his rightful ownership of all the land, but it also increased the stewardship of time, labor, and production over the preceeding 6 years wherein the land had been used and the gains from it enjoyed.
The property was considered to be owned by God, and the use of it according to his purpose and by his assignment.
The governance of God is so totally different from anything which man has designed: It is not socialism. It is not democracy. It is closest to that which we call a republic..... where all are governed by laws and which give equality of justice to all whether they are rich or poor, in a minority or a majority. Its closest economy is to that which we've termed 'capitalism' but still this does not come close, because of the possession and conveyance of property which includes the land..... which God did not allow(i.e. the permanent conveyance of land). The governance of God's plan prevented the 'rich' from taking a permanant possession and control of the land to hoard or use for their limited purpose: It kept the land in the hands of the people to be used to provide for their needs.