Sahih Bukhari Volume 7, Book 69, Hadith 5356

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 ‏"‏‏

Narrated By Sad : The Prophet 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."