كتاب الإمارة
33  
The Book on Government
(37)
Chapter: The virtue of Charity in the Cause of Allah, and its Manifold reward
(37)
باب فَضْلِ الصَّدَقَةِ فِي سَبِيلِ اللَّهِ وَتَضْعِيفِهَا ‏‏
Sahih Muslim 1892 a

It has been narrated on the authority of Abu Mas'ud al-Ansari who said A man brought a muzzled she-camel and said:

It is (offered) in the way of Allah. The Messenger of Allah (ﷺ) said: For this you will have seven hundred she-camels on the Day of Judgment all of which will be muzzled.
حَدَّثَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ الْحَنْظَلِيُّ، أَخْبَرَنَا جَرِيرٌ، عَنِ الأَعْمَشِ، عَنْ أَبِي عَمْرٍو، الشَّيْبَانِيِّ عَنْ أَبِي مَسْعُودٍ الأَنْصَارِيِّ، قَالَ جَاءَ رَجُلٌ بِنَاقَةٍ مَخْطُومَةٍ فَقَالَ هَذِهِ فِي سَبِيلِ اللَّهِ ‏.‏ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏ "‏ لَكَ بِهَا يَوْمَ الْقِيَامَةِ سَبْعُمِائَةِ نَاقِةٍ كُلُّهَا مَخْطُومَةٌ ‏"‏ ‏.‏
Reference : Sahih Muslim 1892a
In-book reference : Book 33, Hadith 193
USC-MSA web (English) reference : Book 20, Hadith 4663
  (deprecated numbering scheme)