Which idiom means: to get information directly from the most reliable source or from the most knowledgeable person?

I heard it straight from the horse's mouth

To learn something through gossip, rather than from the original source

To be waiting eagerly to hear about something

To engage in a rather pointless or passive activity with the goal of making time pass more quickly

To be old-fashioned, not keeping up with current fashions, methods, ideas, or trends

To be open and honest about your feelings and emotions, making them visible to others

To think that someone will feel great jealousy or regret

To be basically kind and have good intentions, even if your actions are sometimes imperfect or don't turn out as planned

Telling someone to wait, slow down, or be patient

A completely different matter or issue, something unrelated to the previous topic being discussed

To supply something to a place or person that already has a lot of that particular thing

To pursue a mistaken course of action, making the wrong assumption, or looking for something in the wrong place

To make the wrong decision and support a person or action that is later unsuccessful

To reveal a secret, either intentionally or accidentally