A little bird told me

Definition

(idiomatic) Of information which was gathered from a source not to be overtly exposed. If we say that a little bird told us something, we mean that we don't want to say who gave us some information. We can talk about the information, but we don't want to reveal the source of the information. So we say, a little bird told me.

Example

1. Let's just say I know because a little bird told me.
2. Parent:"A little bird told me that you have been smoking." Child (embarrassed): "Father!" Parent:"Cigarettes are a waste of money just to be burned up!"

Usage notes: This phrase is often used more comically than seriously, especially when the source of the information is obvious to both parties but neither is willing to say.