A more thorough explanation:

Definition: Livery of seisin was a ceremony used in the past to transfer ownership of land from a grantor to a grantee. The ceremony involved either going on the land and having the grantor symbolically deliver possession of the land to the grantee by handing over a twig, a clod of dirt, or a piece of turf (called livery in deed) or going within sight of the land and having the grantor tell the grantee that possession was being given, followed by the grantee's entering the land (called livery in law).

Example: In the past, when someone wanted to transfer ownership of land to another person, they would perform a ceremony called livery of seisin. For example, the transferor and transferee would go to the land to be transferred, and the transferor would then hand to the transferee a lump of soil or a twig from a tree, while intoning the appropriate words of grant, together with the magical words "and his heirs" if the interest transferred was to be a potentially infinite one.

Explanation: The example illustrates how livery of seisin was performed in the past. The transferor and transferee would go to the land to be transferred, and the transferor would then hand over a twig, a clod of dirt, or a piece of turf to the transferee, symbolically transferring ownership of the land. This ceremony was used to mark the transfer of ownership and give notice to interested persons such as the mesne lord above the transferor.