the prophet sallAllahu 'alaihi wasallam said to ali: you are to me like harun was to musa. the shia use this hadith to claim ali is khalifa bila fasl because they say harun was the khalifa of musa without fasl. --- they are wrong because: 1. harun was older than musa 2. harun passed away before musa and musa prayed his janaza [alayhima's-salatu wa's salam] the reason the hadith was said was because: 1. the prophet's male progeny passed away in infancy or childhood. the prophet's lineage was through ali's children. similarly, musa didn't have male children and harun did and musa's was known through harun's children. 2. harun built a mosque in egypt and only he and musa could pass through it even in janaba. same with rasulAllah sallAllahu 'alaihi wasallam and ali. 3. during tabuk, the prophet sallAllahu 'alaihi wasallam left ali in madina to look after the family. similarly, musa left harun when he went to tur. --- so, the shia need to learn hadith and tarikh before making stupid claims.