Qabil and Habil

Salaamun Alaykum

Thank you for question.

What is apparent is that Qabil kills Habil out of jealousy. The reason was that God accepted the offering of Habil, whereas He rejected the offering of Qabil. The Qur'an indicates that the reason for this was that whereas Habil was a muttaqi, Qabil was not.

5:27

وَاتْلُ عَلَيْهِمْ نَبَأَ ابْنَيْ آدَمَ بِالْحَقِّ إِذْ قَرَّبَا قُرْبَانًا فَتُقُبِّلَ مِنْ أَحَدِهِمَا وَلَمْ يُتَقَبَّلْ مِنَ الْآخَرِ قَالَ لَأَقْتُلَنَّكَ ۖ قَالَ إِنَّمَا يَتَقَبَّلُ اللَّهُ مِنَ الْمُتَّقِينَ

He said: I will most certainly slay you.

(The other) said: God only accepts from the muttaqeen.

Some have suggested that Qabil's offering was smaller, or in other ways different. This is reading into the text what is not there. 

Yet some have suggested other reasons for the jealousy of Qabil, but again, this would entail reading in things into the Qur'an which is not there.

In need of your prayers,
Hassanain