Muhammad bin Abdullah bin Atik of Banu Salimah narrates from his father (may Allah be pleased with him): I heard the Messenger of Allah (peace and blessings be upon him) say: "Whoever leaves his house with the intention of jihad in the way of Allah." The narrator said: Then he (peace and blessings be upon him) joined his three fingers together and said: "Where are those who strive in the way of Allah? Whoever falls from his mount in the way of Allah and dies, his matter rests with Allah; and if he dies from being stung by something, he will receive the full reward; and whoever dies a natural death." The narrator said: This is a word I had not heard from any Arab before the Messenger of Allah (peace and blessings be upon him), meaning the one who dies on his bed: "his reward too rests with Allah; and whoever is killed on the spot has made Paradise obligatory for himself."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السير / 18536