Under Section 10 of the Transfer of Property Act, 1882, any absolute restraint on alienation of property is considered void. This means that if a transfer of property is made subject to a condition that completely prohibits the transferee (recipient of the property) from transferring the property further, such a condition is legally unenforceable.

Meaning of Absolute Restraint:
An absolute restraint is a condition that entirely restricts the transferee's right to sell, gift, mortgage, lease, or otherwise transfer the property. For example, if a gift deed says "A gives land to B on the condition that B shall never sell it," that condition is void under Section 10.

Legal Effect:
The transfer itself remains valid, but the condition imposing absolute restraint is void.
The transferee gets full ownership rights, including the right to transfer.
Partial restraints, if reasonable (such as a restriction for a certain time or purpose), may be valid in some cases.

Exceptions:
There are exceptions under Section 10 itself and other provisions:
Leasehold interests: Restrictions on transfer in leases are valid.
Transfer to women under Hindu Law: Traditionally, under certain personal laws, restrictions were allowed (though largely outdated today).
Trusts and certain settlements: If property is held in trust, the trustee's powers may be lawfully limited.

Judicial View:
Courts have consistently held that the right to transfer property is a key incident of ownership. In Rosher v. Rosher (a British case often cited in India), a condition that prevented the sale of property except to a specific person at a fixed price was held void.