This is a Spanish idiomatic expression that means 'One preaches well, who lives well.' It's used to express the idea that one's actions speak louder than words or that one should practice what they preach.
Examples
- Spanish: No puedes aconsejar a alguien sobre cómo ahorrar dinero si tú mismo eres derrochador. Bien predica, quien bien vive.
- English: You can't advise someone on how to save money if you are a spendthrift yourself. He preaches well, who lives well.