We know that we fast on the day of ashura coz that day was the day when Allah saved Musa (PBUH) and his followers.
Ka  dib  bal  aan  wax  yar  ka  nidhaahno  ninka  la  filaayo  in  bari    oo  ah  maalin  salaaso  ah  haduu  alleh  idmo  noqon  doono  murashaxa  xisbiga  kulmiye  ee  doorshada  soo  socota  muuse  biixi  waan  ku  hambaleynayaa  samirkiisa  iyo  adkeysigiisa  uu  halkaasi  ku  soo  gaadhey  marka  hore.