你若将心比心我便以心换心
[nĭ ruò jiāng xīn bĭ xīn wŏ biàn yĭ xīn huàn xīn]
This phrase means 'If you treat me sincerely, I will reciprocate with equal sincerity'. It is an expression of mutual understanding and reciprocity in relationships, emphasizing treating each other with empathy, respect, and equality.