Aap (S.A.W) ne Farmaya:
Mai ILM ka Sheher hon
Abu Bakar us Sheher ki Bunyad hai
Or
Umer uski Deewar hai
Or
Usman uski Chhat hai
Or
Ali uska Darwaza hai.
(Sahi AlBukhari
Nazhat-ul-majalis,v:2, page:214)
Ye mukamal Hadis hai.
Kuch log iska sirf pehla or akhri hissa bayan karte hain.
Plz Fwd to clear others.