3.  she  took  for  him  an  ark  of  bulrushes--papyrus,  a  thick,  
  strong,  and  tough  reed.
  
         
  slime--the  mud  of  the  Nile,  which,  when  hardened,  is  very  
  tenacious.
  
         
  pitch--mineral  tar.  Boats  of  this  description  are  seen  daily  
  floating  on  the  surface  of  the  river,  with  no  other  caulking  than  Nile  
  mud  (compare
  Isa  18:2),
  and  they  are  perfectly  watertight,  unless  the  coating  is  forced  off  by  
  stormy  weather.
  
         
  flags--a  general  term  for  sea  or river weed.  The chest was  not,  
  as  is  often  represented,  committed  to  the  bosom  of  the  water  but  laid  
  on  the  bank,  where  it  would  naturally  appear  to  have  been  drifted  by  
  the  current  and  arrested  by  the  reedy  thicket.  The  spot  is  
  traditionally  said  to  be  the  Isle  of  Rodah,  near  Old  Cairo.
JFB.
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