Psa 7:11 God judgeth the righteous, and God is angry
with the wicked every day.
Psa 7:12 If he turn not, he will whet his sword; he hath bent his bow, and made it ready.
Psa 7:13 He hath also prepared for him the instruments of death; he ordaineth his arrows against the persecutors.
Psa 7:14 Behold, he travaileth with iniquity, and hath conceived mischief, and brought forth falsehood.
Psa 7:15 He made a pit, and digged it, and is fallen into the ditch
which he made.
NLT: The wicked conceive evil;
they are pregnant with trouble
and give birth to lies.
So I hear Jesus say it this way:
Mat 15:18 But those things which proceed out of the mouth come forth from the heart; and they defile the man.
Mat 15:19 For out of the heart proceed evil thoughts, murders, adulteries, fornications, thefts, false witness, blasphemies:
The conceiving evil is the thoughts of the heart, and if left unchecked they will turn into an action of doing them.
Enough hatred of something can lead you to harming or killing whatever you hate.