Sahih Muslim Book 20, Hadith Number 4630.

Chapter : The merit of Jihad and campaigning in the way of Allah.

It has been narrated on the authority of Abu Haraira that the Messenger of Allah (may peace be upon him) said: Every wound received by a Muslim in the way of Allah will appear on the Day of Judgment in the same condition as it was when it was inflicted, and would be bleeding profusely. The colour (of its discharge) will be the colour of blood, but its smell will be the smell of musk. By the Being in Whose Hand is Muhammad’s life, if it were not hard upon the Muslims, I would not lag behind any expedition undertaken for Jihad, but I do not possess abundant means to provide the Mujahids with riding animals, nor do they (i.e. all of them) have abundant means (to provide themselves with all the means of Jihad) to follow me, nor would it please their hearts to stay behind me.