Japanese DictionaryDefinition of 情けは人の為ならず
- (exp) the good you do for others is good you do yourself; compassion is not for other people's benefit
これは絶対、情けは人のためならず！いいことしたからご褒美なんだよ！
This is definitely, 'The good you do for others is good you do yourself'! It's a reward because I was helpful!