The UAE has an unfunded mandatory end-of-service gratuity.  It is payable upon termination of an employment.  That would be taxed as compensation in the year it was paid but you need to sourced it over the period of employment to reflect how the entitlement is computed.

If you are talking about provident fund or pension, there is not a mandatory scheme yet although the government has been toying with that idea for years.  I am not personally aware of any major company offering that to expats on a voluntary basis.  If your client also did participate in a voluntary company-sponsored provident fund/pension scheme, please let us know as that would be a different kettle of fish.