Language:
كتاب الوصايا
55  
Wills and Testaments (Wasaayaa)
(12)
Chapter: Can the founder of an endowment have the benefit of his endowment?
(12)
باب هَلْ يَنْتَفِعُ الْوَاقِفُ بِوَقْفِهِ
Sahih al-Bukhari 2754

Narrated Anas:

The Prophet (ﷺ) saw a man driving a Badana (i.e. camel for sacrifice) and said to him, "Ride on it." The man said, "O Allah's Messenger (ﷺ)! It is a Bandana." (The Prophet (ﷺ) repeated his order) and on the third or fourth time he said, "Ride it, (woe to you" or said: "May Allah be merciful to you).

حَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، حَدَّثَنَا أَبُو عَوَانَةَ، عَنْ قَتَادَةَ، عَنْ أَنَسٍ ـ رضى الله عنه ـ أَنَّ النَّبِيَّ صلى الله عليه وسلم رَأَى رَجُلاً يَسُوقُ بَدَنَةً، فَقَالَ لَهُ ‏"‏ ارْكَبْهَا ‏"‏‏.‏ فَقَالَ يَا رَسُولَ اللَّهِ إِنَّهَا بَدَنَةٌ‏.‏ قَالَ فِي الثَّالِثَةِ أَوِ الرَّابِعَةِ ‏"‏ ارْكَبْهَا، وَيْلَكَ، أَوْ وَيْحَكَ ‏"‏‏.‏
Reference : Sahih al-Bukhari 2754
In-book reference : Book 55, Hadith 17
USC-MSA web (English) reference : Vol. 4, Book 51, Hadith 17
  (deprecated numbering scheme)