百善孝为先万恶淫为源
[băi shàn xiào wéi xiān wàn è yín wéi yuán]
'Among all virtues, filial piety is first; among all evils, licentiousness is the root' reflects traditional Chinese moral values emphasizing respect for parents and elders ('filial piety') above all else and warns against excessive indulgence which might lead to undesirable outcomes.