Imaam Ibnul Jawzi [rahimahullaah] said:

Envy is the most despicable trait. The first deed of disobedience through which Allaah was disobeyed in the heavens was Iblees’s envy towards Aadam and the [first deed of disobedience through which Allaah was disobeyed] in the earth was Qaabil’s envy toward Haabil.


[Source: Zaadul Maseer’ [Tafseer Surah Al-Falaq]- by Ibn Jawzi (rahimahullaah)]