كتاب الزكاة
12  
The Book of Zakat
(19)
Chapter: Acceptance of charity that comes from good (Tayyib) earnings, and the growth thereof
(19)
باب قَبُولِ الصَّدَقَةِ مِنَ الْكَسْبِ الطَّيِّبِ وَتَرْبِيَتِهَا ‏‏
Sahih Muslim 1014 a

Abu Huraira reported Allah's Messenger (ﷺ) as saying:

If anyone gives as Sadaqa the equivalent of a date from that (earning) earned honestly, for Allah accepts that which is lawful, the Lord would accept it with His Right Hand, and even if it is a date, it would foster in the Hand of the lord, as one of you fosters his colt, till it becomes bigger than a mountain.
وَحَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، حَدَّثَنَا لَيْثٌ، عَنْ سَعِيدِ بْنِ أَبِي سَعِيدٍ، عَنْ سَعِيدِ بْنِ يَسَارٍ، أَنَّهُ سَمِعَ أَبَا هُرَيْرَةَ، يَقُولُ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏ "‏ مَا تَصَدَّقَ أَحَدٌ بِصَدَقَةٍ مِنْ طَيِّبٍ - وَلاَ يَقْبَلُ اللَّهُ إِلاَّ الطَّيِّبَ - إِلاَّ أَخَذَهَا الرَّحْمَنُ بِيَمِينِهِ وَإِنْ كَانَتْ تَمْرَةً فَتَرْبُو فِي كَفِّ الرَّحْمَنِ حَتَّى تَكُونَ أَعْظَمَ مِنَ الْجَبَلِ كَمَا يُرَبِّي أَحَدُكُمْ فَلُوَّهُ أَوْ فَصِيلَهُ ‏"‏ ‏.‏
Reference : Sahih Muslim 1014a
In-book reference : Book 12, Hadith 79
USC-MSA web (English) reference : Book 5, Hadith 2211
  (deprecated numbering scheme)