Sahih al-Bukhari 4676
Narrated `Abdullah bin Ka`b:
I heard Ka`b bin Malik talking about the Verse:-- 'And to the three (He also forgave) who remained 
behind.' (9.118) saying in the last portion of his talk, "(I said), 'As a part (sign) of my repentance, I 
would like to give up all my property in the cause of Allah and His Apostle,' The Prophet (ﷺ) said to me, 
'Keep some of your wealth as it is good for you." (To the three (He also forgave) who remained 
behind till for them the earth, vast as it is, was straitened..." (9.118)
حَدَّثَنَا أَحْمَدُ بْنُ صَالِحٍ، قَالَ حَدَّثَنِي ابْنُ وَهْبٍ، قَالَ أَخْبَرَنِي يُونُسُ، قَالَ أَحْمَدُ حَدَّثَنَا عَنْبَسَةُ، حَدَّثَنَا يُونُسُ، عَنِ ابْنِ شِهَابٍ، قَالَ أَخْبَرَنِي عَبْدُ الرَّحْمَنِ بْنُ كَعْبٍ، قَالَ أَخْبَرَنِي عَبْدُ اللَّهِ بْنُ كَعْبٍ ـ وَكَانَ قَائِدَ كَعْبٍ مِنْ بَنِيهِ حِينَ عَمِيَ ـ قَالَ سَمِعْتُ كَعْبَ بْنَ مَالِكٍ، فِي حَدِيثِهِ ‏{‏وَعَلَى الثَّلاَثَةِ الَّذِينَ خُلِّفُوا‏}‏ قَالَ فِي آخِرِ حَدِيثِهِ إِنَّ مِنْ تَوْبَتِي أَنْ أَنْخَلِعَ مِنْ مَالِي صَدَقَةً إِلَى اللَّهِ وَرَسُولِهِ‏.‏ فَقَالَ النَّبِيُّ صلى الله عليه وسلم ‏"‏ أَمْسِكْ بَعْضَ مَالِكَ، فَهْوَ خَيْرٌ لَكَ ‏"‏‏.‏