It is narrated from Hazrat Hudhaifa (may Allah be pleased with him) that the Holy Prophet (peace and blessings be upon him) said: When the Dajjal appears, he will have with him water and fire. What will appear to people as fire will actually be cool water, and what will appear as water will actually be burning fire. Therefore, do not be destroyed. Upon hearing this hadith, Hazrat Abu Mas'ud (may Allah be pleased with him) said: I have heard this hadith from the Holy Prophet (peace and blessings be upon him).