I was on the phone with a relative. They were complaining about a run-in with another relative and starting a familiar litany of the person's failings. I said, "Yes, but even given all that, have you ever noticed that _______ is one terrific listener? She's always willing to put her concerns on hold and listen when you need her to." That made for a shorter conversation, but when it was over I felt purified, the way passing up an opportunity to engage in negativity gossip always makes us feel.
"There is nothing outside a person that by going in can defile, but the things that come out are what defile" (Mk. 7:15).
Most people get heart checkups and start watching what goes into their mouths. Jesus recommends that we check out our hearts and then start watching what comes out of them!