Al-Ma'idah Verse 31

Then Allah sent a crow digging ˹a grave˺ in the ground ˹for a dead crow˺, in order to show him how to bury the corpse of his brother. He cried, “Alas! Have I ˹even˺ failed to be like this crow and bury the corpse of my brother?” So he became regretful.[[ In Islam, regret for doing something wrong is essential for repentance. But in the case of Cain, his regret was not for killing his brother, but for failing to bury his corpse to hide the evidence of his crime. Therefore, his regret was not intended as a step towards repentance. ]] 

Then Allah sent a crow scratching the ground to show him how to bury the corpse of his brother. He said, “Woe to me! Have I failed even to be like this crow to bury the corpse of my brother?” And he became one of the remorseful.

Then God sent forth a raven, scratching into the earth, to show him how he might conceal the vile body of his brother. He said, 'Woe is me! Am I unable to be as this raven, and so conceal my brother's vile body?' And he became one of the remorseful.

God sent a raven to scratch up the ground and show him how to cover his brother’s corpse and he said, ‘Woe is me! Could I not have been like this raven and covered up my brother’s body?’ He became remorseful.

Then Allah sent a raven scratching in the earth to show him in what wise he might cover the corpse of his brother. He said: woe unto me was incapable of being like unto this raven so that I might cover the corpse of my brother! And he became of the remorseful.

Then Allah sent a raven, who scratched the ground, to show him how to hide the shame of his brother. "Woe is me!" said he; "Was I not even able to be as this raven, and to hide the shame of my brother?" then he became full of regrets-

Thereupon Allah sent forth a raven who began to scratch the earth to show him how he might cover the corpse of his brother. So seeing he cried: 'Woe unto me! Was I unable even to be like this raven and find a way to cover the corpse of my brother? Then he became full of remorse at his doing.

Then God sent a raven which scratched the ground in order to show him how to hide the nakedness of his brother. "Alas, the woe," said he, "that I could not be even like the raven and hide the nakedness of my brother," and was filled with remorse.

So Allah sent a crow scratching the ground, to show him how to hide his brother’s corpse; he said, “Woe to me! I was not even capable enough to be like this crow, so I would hide my brother’s corpse”; and he turned remorseful.

Then Allah sent a crow, exploring in the ground, to show him how to bury the corpse of his brother. He said, ‘Woe to me! Am I unable to be [even] like this crow and bury my brother’s corpse?’ Thus he became regretful.

(He did not know what to do with the dead body of his brother.) Then God sent forth a raven, scratching in the earth, to show him how he might cover the corpse of his brother. (So seeing) he cried: "Oh, alas for me! Am I then unable even to be like this raven, and so find a way to cover the corpse of my brother?" And he became distraught with remorse.

Then Allâh sent a raven which scratched into the earth so as to show him how he might cover his brother´s dead body. He said, `Woe is me! Am I unable to be even like this raven so that I may cover the dead body of my brother?´ And he became one of the remorseful.

So God sent a crow digging/searching in the earht/Planet Earth, to show him how (he) hides/conceals his brother`s shameful genital private part to be covered, he said: "Oh my calamity , have I been unable that I be similar/like that the crow, so I hide/conceal my brother`s shameful genital private part to be covered?" So he became from the regretful/sorrowful/remorseful.

So Allah sent a crow scratching the ground, to show him how to hide his brother’s corpse; he said, “Woe to me! I was not even capable enough to be like this crow, so I would hide my brother’s corpse”; and he turned remorseful.

For this cause have We prescribed to the children of Israel that whoever kills a soul, unless it be for murder or for mischief (or corruption) in the land, it would be as though he had killed all mankind; but whoever saves the life of one, it would be as though he had saved mankind. Our Messenger came to them in the past with manifest signs, afterwards, verily, many of them commit excesses in the earth.

Then Allah sent a crow who scratched the ground to show him to hide the dead body of his brother. He (the murderer) said: "Woe to me! Am I not even able to be as this crow and to hide the dead body of my brother?" Then he became one of those who regretted.

At length his mind made it easy for him to kill his brother, so he killed him; so he became one of the losers.

Then Allah sent a crow digging up the earth so that he might show him how he should cover the dead body of his brother. He said: Woe me! do I lack the strength that I should be like this crow and cover the dead body of my brother? So he became of those who regret.

Then Allah sent a raven scratching up the ground, to show him how to hide his brother's naked corpse. He said: Woe unto me! Am I not able to be as this raven and so hide my brother's naked corpse? And he became repentant.

God sent down a raven which started to dig up the earth to show the killer how to bury the corpse of his brother. On seeing the raven, (Cain) said, "Woe to me! Am I less able than a raven to bury the corpse of my brother?" He became greatly remorseful.

Then Allah sent down a crow, which dug the earth to show him how to bury the naked corpse of his brother. 'Alas' he said, 'am I unable to be like this crow and so I bury my brother's naked corpse' And he became among those who regret.

Then Allah sent a crow who scratched the ground to show him how to hide the dead body of his brother. He said: "Woe to me! Am I not even able to be as this crow and to hide the dead body of my brother" Then he became one of those who regretted.

Then God sent a raven, which scratched the earth, so that He might show him how to hide the corpse of his brother. "Alas!" he cried, "Am I not able even to be like this raven, so that I may hide the corpse of my brother?" And he repented.

Then God sent a raven digging the ground, to show him how to cover his brother's corpse. He said, “Woe to me! I was unable to be like this raven, and bury my brother's corpse.” So he became full of regrets.

Then God sent forth a raven, scratching into the earth, digging up the soil with its beak and with its legs and throwing it up over a dead raven next to it until it completely hid it, to show him how he might hide the nakedness, the carcass, of his brother. He said, `Woe to me! Am I not able to be as this raven, and so hide my brother's nakedness?' And he became one of the remorseful, for having carried him; he then dug [a hole] for him and covered him up.

Then Allah sent a crow who scratched the ground to show him how to hide the dead body of his brother. He (the murderer) said, "Woe to me! Am I not even able to be as this crow and to hide the dead body of my brother!" Then he became one of those who regretted.

As-Suddi said that the Companions said,

"When his brother died, Qabil left him on the bare ground and did not know how to bury him. Allah sent two crows, which fought with each other until one of them killed the other. So it dug a hole and threw sand over the dead corpse (which it placed in the hole). When Qabil saw that, he said,
يَا وَيْلَتَا أَعَجَزْتُ أَنْ أَكُونَ مِثْلَ هَـذَا الْغُرَابِ فَأُوَارِيَ سَوْءةَ أَخِي
("Woe to me! Am I not even able to be as this crow and to hide the dead body of my brother!").

Ali bin Abi Talhah reported that Ibn Abbas said,

"A crow came to the dead corpse of another crow and threw sand over it, until it hid it in the ground. He who killed his brother said,
يَا وَيْلَتَا أَعَجَزْتُ أَنْ أَكُونَ مِثْلَ هَـذَا الْغُرَابِ فَأُوَارِيَ سَوْءةَ أَخِي
(Woe to me! Am I not even able to be as this crow and to hide the dead body of my brother!)."

Al-Hasan Al-Basri commented on the statement,
فَأَصْبَحَ مِنَ النَّادِمِينَ
(Then he became one of those who regretted).

"Allah made him feel sorrow after the loss that he earned."
The Swift Punishment for Transgression and Cutting the Relations of the Womb

A Hadith states that the Prophet said,

مَا مِنْ ذَنْبٍ أَجْدَرُ أَنْ يُعَجِّلَ اللهُ عُقُوبَتَهُ فِي الدُّنْيَا مَعَ مَا يَدَّخِرُ لِصَاحِبهِ فِي الاْاخِرَةِ مِنَ الْبَغْيِ وَقَطِيعَةِ الرَّحِم

There is no sin that is more worthy of Allah hastening its punishment in this life, in addition to what He has in store for its offender in the Hereafter, more than transgression and cutting the relations of the womb.

The act of Qabil included both of these.

We are Allah's and to Him is our return