The 18th prohibition is that we are forbidden from easing our hatred of the meisis. One is absolutely required to maintain this hatred, and if one does not do so, one transgresses a prohibition.

The source of this commandment is G‑d's statement (exalted be He),1 "And do not listen to him."

The explanation of this is: "Since it is written2 [regarding someone you hate3], 'You must make every effort to help him,' one might imply that you may4 help even this [meisis]. The verse therefore says,5 "And do not listen to him."