Sahih Muslim | Book 20 | Hadith Number 4706

Narrated by Abu Huraira
It has been narrated on the authority of Abu Huraira (through another chain of transmitters) that the Messenger of Allah (may peace be upon him) said: Whom do you consider to be a martyr among you? They (the Companions) said: Messenger, of Allah, one who is slain in the way of Allah is a martyr. He said: Then (if this is the definition of a martyr) the martyrs of my Umma will be small in number. They asked: Messenger of Allah, who are they? He said: One who is slain in the way of Allah is a martyr; one who dies in the way of Allah, is a martyr; one who dies of plague is a martyr; one who dies of cholera is a martyr.

Ibn Miqsam said: I testify the truth of your father's statement (with regard to this tradition) that the Holy Prophet (may peace be upon him) said: One who is drowned is a martyr.