Sahih Bukhari
Oaths and Vows
Volume: 008 / Book Number: 078 / Hadith Number: 669
Narrated Abu Musa:
My companions sent me to the Prophet to ask him for some mounts. He said, "By Allah! I will not mount you on anything!" When I met him, he was in an angry mood, but when I met him (again), he said, "Tell your companions that Allah or Allah's Apostle will provide you with mounts."