Sahih al-Bukhari 5354
Narrated Sa`d:
The Prophet (ﷺ) visited me at Mecca while I was ill. I said (to him), "I have property; May I bequeath all 
my property in Allah's Cause?" He said, "No." I said, "Half of it?" He said, "No." I said, "One third of 
it?" He said, "One-third (is alright), yet it is still too much, for you'd better leave your inheritors 
wealthy than leave them poor, begging of others. Whatever you spend will be considered a Sadaqa for 
you, even the mouthful of food you put in the mouth of your wife. Anyhow Allah may let you recover, 
so that some people may benefit by you and others be harmed by you."
حَدَّثَنَا مُحَمَّدُ بْنُ كَثِيرٍ، أَخْبَرَنَا سُفْيَانُ، عَنْ سَعْدِ بْنِ إِبْرَاهِيمَ، عَنْ عَامِرِ بْنِ سَعْدٍ، عَنْ سَعْد ٍ ـ رضى الله عنه ـ قَالَ كَانَ النَّبِيُّ صلى الله عليه وسلم يَعُودُنِي وَأَنَا مَرِيضٌ بِمَكَّةَ، فَقُلْتُ لِي مَالٌ أُوصِي بِمَالِي كُلِّهِ قَالَ ‏"‏ لاَ ‏"‏‏.‏ قُلْتُ فَالشَّطْرُ قَالَ ‏"‏ لاَ ‏"‏‏.‏ قُلْتُ فَالثُّلُثُ قَالَ ‏"‏ الثُّلُثُ، وَالثُّلُثُ كَثِيرٌ، أَنْ تَدَعَ وَرَثَتَكَ أَغْنِيَاءَ خَيْرٌ مِنْ أَنْ تَدَعَهُمْ عَالَةً، يَتَكَفَّفُونَ النَّاسَ فِي أَيْدِيهِمْ، وَمَهْمَا أَنْفَقْتَ فَهُوَ لَكَ صَدَقَةٌ حَتَّى اللُّقْمَةَ تَرْفَعُهَا فِي فِي امْرَأَتِكَ، وَلَعَلَّ اللَّهَ يَرْفَعُكَ، يَنْتَفِعُ بِكَ نَاسٌ وَيُضَرُّ بِكَ آخَرُونَ ‏"‏‏.‏