常备狗粮常买刀喂饱贱人捅一刀
[cháng bèi gŏu liáng cháng măi dāo wèi băo jiàn rén tŏng yī dāo]
This contains slang with a negative and aggressive connotation, suggesting someone has an antagonistic relationship. It involves preparing dog food (a euphemism), providing tools (swords), and feeding someone only to later betray or attack them ('cheap/despised people' may refer to disrespected individuals).