What is y all come back now ya hear?

"Y'all come back now, ya hear?" is a friendly farewell commonly used in the Southern United States. It is often used when someone is leaving a gathering or event and is meant to convey a sincere invitation for the person to return in the future. The phrase became popularized in the 1960s through the popular television show "The Beverly Hillbillies." Since then, it has become a widely recognized expression of Southern hospitality.