Hazrat Abu Huraira (may Allah be pleased with him) narrated that the Messenger of Allah (peace and blessings be upon him) said: A man was going somewhere. On the way, he saw a branch full of thorns, so he removed it from the path. Allah Almighty (just because of this act) became pleased and forgave him. Then the Prophet (peace and blessings be upon him) said that martyrs are of five kinds: those who die in a plague, those who die of stomach ailments (such as cholera, etc.), those who drown, those who die by being crushed by a wall or any other thing, and those who are martyred in the way of Allah (while fighting in jihad).

Hazrat Anas bin Malik (may Allah be pleased with him) narrated that the Prophet Muhammad (peace and blessings be upon him) said: Death by plague is considered martyrdom for every Muslim.