Sahih Muslim Book 20, Hadith Number 4667.

Chapter : The merit of helping the warrior (fighting in the way of Allah) with something to ride upon and looking after his family in his absence.

It has been narrated on the authority of Anas b. Malik that a young man from Aslam tribe said: Messenger of Allah, I wish to fight (in the way of Allah) but I don’t have anything to equip myself with for fighting. He (the Holy Prophet) said: Go to so and so, for he had equipped himself (for fighting) but he fell ill. So, he (the young man) went to him and said: The Messenger of Allah (may peace be upon him) sends you his greetings and says that you should give me the equipage that you have provided yourself with. The man said (to his wife or maidservant): So and so, give him the equipage I have collected for myself and do not withhold anything from him. Do not withhold anything from him so that you may be blessed therein.