Possession is nine points/tenths/parts of the law American British proverb
A proverb used to express that someone have strong possession over something after a long time of using/keeping it. Others can not take it away from he/she, even if they have the legal rights to do so.
"The book is mine, but she's kept it for a long time, it's hard to take it back, possesion is nine parts of the law."
The attorney said to me:"You have the advantage of owning the land, but they've lived there for so long, possesion is nine points of the law."
To possess something very valuable, especially without realizing it
This expression dates around the 17th century.
Daughter: So I really want all my friends to have a great time. I was thinking it would be a good idea to have some candy out on the tables for people to snack on.
Mother: Well, if you want them to really enjoy themselves, candy is dandy but liquor is quicker.