Read and reflect on verse 700 from Surah Al-Maaida: 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...
فَبَعَثَ اللَّهُ غُرَابًا يَبْحَثُ فِي الْأَرْضِ لِيُرِيَهُ كَيْفَ يُوَارِي سَوْءَةَ أَخِيهِ ۚ قَالَ يَا وَيْلَتَا أَعَجَزْتُ أَنْ أَكُونَ مِثْلَ هَٰذَا الْغُرَابِ فَأُوَارِيَ سَوْءَةَ أَخِي ۖ فَأَصْبَحَ مِنَ النَّادِمِينَ
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, and to conceal the nakedness of my brother's body?" - and was thereupon smitten with remorse.