Full Idea
Hume thought (in contrast to Locke) that property reflects a conventional (rather than natural) relationship determined by the laws that protect people from having things taken from them.
Gist of Idea
Hume thought (unlike Locke) that property is a merely conventional relationship
Source
report of David Hume (Nine political essays [1741]) by Robert Fogelin - Walking the Tightrope of Reason Ch.3
Book Reference
Fogelin,Robert: 'Walking the Tightrope of Reason' [OUP 2004], p.75
A Reaction
It seems pretty obvious that the idea of property was invented by the powerful, to protect their gains against the weak. I suspect that you might till a piece of land simply in order to assert ownership of it, just as you might bring in colonists.