There are six things that the LORD hates, seven that are an abomination to him: haughty eyes, a lying tongue, and hands that shed innocent blood, a heart that devises wicked plans, feet that make haste to run to evil, a false witness who breathes out lies, and one who sows discord among brothers (Prov. 6:16-19, ESV).
These seven deadly sins reflect sinful personalities. The first five deadly sins are symbolized by body parts from the head to the feet (eyes, tongue, hands, heart, and feet). The last two deadly sins refer to two types of persons—the false witness and troublemaker. Thus, God hates haughty eyes (a proud, arrogant person). God hates a lying tongue (a liar). God also hates a killer (a murderer or possibly one who harms others physically or psychologically).
Our focus is on v. 18. God hates a person who makes “wicked plans.” The word, “wicked” (Heb. aven), means, “thoughts of trouble, wicked imaginations.” (BDB) The word is set in the context of pride, lying, and violence. Thus, it can mean, wicked thoughts and plans driven by pride, falsehood, and an intent to harm other people.
This is the kind of planning that you should not make anytime. Do not think evil plans. Your plans should not be driven by your pride. Your plans should not be marked by falsehood. Your plans should be devoid of any intent to bring evil to others.