Sayyiduna Mu'adh bin Jabal (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) said: "Whoever sincerely wishes for martyrdom and then dies or is killed will be given the reward of martyrdom; and whoever is wounded in the way of Allah, his wound will be flowing with blood, its colour like blood and its scent like musk."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السير / 18558