A saying from the 1991 movie Robin Hood. It is used now to inform people that something weird is about to go down. It is mainly used while under the influence of alcohol. The person who said it usually follows it up by doing something that cannot be comprehended by any normal human being.
Mike quickly slammed down two 99 Blackberries and yelled out "To The Trees!". Right after, a grapefruit was thrown through the neighbors window.