一把刀狠狠地插入他的心脏
[yī bă dāo hĕn hĕn dì chā rù tā de xīn zàng]
Literal translation is 'Inserting a knife deeply into his heart,' symbolizing a feeling of hatred or deep grievance against someone. This expresses extreme emotions of anger and betrayal, but it is important to understand that such phrases are not intended as actual violent threats on the internet.