The Quran

فَبَعَثَ اللَّهُ غُرابًا يَبحَثُ فِي الأَرضِ لِيُرِيَهُ كَيفَ يُواري سَوءَةَ أَخيهِ ۚ قالَ يا وَيلَتا أَعَجَزتُ أَن أَكونَ مِثلَ هٰذَا الغُرابِ فَأُوارِيَ سَوءَةَ أَخي ۖ فَأَصبَحَ مِنَ النّادِمينَ

Muhammad Asad

Thereupon God sent forth a raven which scratched the earth, to show him how he might conceal the nakedness of his brother's body. [And Cain] cried out: "Oh, woe is me! Am I then too weak to do what this raven did,¹ and to conceal the nakedness of my brother's body?" - and was thereupon smitten with remorse.²

Lit., "to be like this raven".
Lit., "became of those who feel remorse". The thought of burying his dead brother's body, suggested to Cain by the raven's scratching the earth, brought home to him the enormity of his crime.