Sahih Muslim
The Book on Government (Kitab Al-Imara)
Book Number: 020 / Hadith Number: 4665
It has been narrated on the authority of Abu Mas'ud al-Ansari who said: A man came to the Messenger of Allah (may peace be upon him) and said: My riding beast has been killed, so give me some animal to ride upon. He (the Holy Prophet) said: I have none with me. A man said: Messenger of Allah, I can guide him to one who will provide him with a riding beast. The Messenger of Allah (may peace be upon him) said: One who guides to something good has a reward similar to that of its doer.