This phrase is not necessarily a slang, but rather a common saying in Spanish which means 'He who lives well, dies well'. It emphasizes the idea that if you live a good, fulfilling life, you will have a peaceful death.
Examples
- Spanish: No se preocupe por las riquezas materiales, recuerde que 'el que vive bien, muere bien'.
- English: Don't worry about material wealth, remember that 'he who lives well, dies well'.