'the reason why dajjal is called as dajjal is because he displays everything in contrariety.
again, in the same section and the same chapter of the afore-said book, the author narrates from bukhari and he from anas-ibn-malik and he from the holy prophet (s.a.w.a.) as such:
'there is no prophet but that whose nation terrifies the ominous and mendacious dajjal....'
ibn-hajar in 'sawa'eq' (page 99) has narrated from abul-hussein abari as such:
'abundant traditions related by successive hearsay have come down from the holy prophet (s.a.w.a.)regarding Mahdi's emergence; concerning the fact that hazrat is from the progeny of the holy prophet (s.a.w.a.); that he will rule for seven years; that he will fill the earth with justice; that he will emerge along with isa and the latter would help him in killing dajjal....
'i heard the messenger of Allah (s.a.w.a.) saying: this house shall remain safe from an army which would attack it until the army takes position in a soft land. the centre row would sink in the ground while the first row would seek help from the last row. then no one shall remain from them except the one who will inform about them.
a person addressed abdullah-ibn-safwan as such: i bear witness that you have not lied about hafsah and she too has not lied about the holy prophet (s.a.w.a.).
this tradition has been narrated by imam muslim in his book 'sahih'.