The Hour will not come until you fight the Jews: until the stone behind which a Jew will be hiding will say: O Muslim, this is a Jew behind me; kill him

The Prophet (may Allah's peace and blessings be upon him) reported that the Hour will not occur until the Muslims and the Jews fight each other - until when a Jew flees to hide behind a stone from the Muslims, Allah will make the stone speak and it will call out to the Muslim that there is a Jew behind it, so that he will go and kill him.