百善孝为先万恶淫为首
[băi shàn xiào wéi xiān wàn è yín wéi shŏu]
This means 'Filial piety is first among all good deeds; lust is the root of all evils.' It emphasizes traditional Chinese values on respect for one's parents and elders while criticizing indulgence in sexual activity outside socially approved norms.