Answer
It is permissible for a Sayyid Hashimi to give his sadaqa to another Sayyid or to a non-Sayyid. This includes both Zakat of property and Zakat of Fitra. But it is not permissible for a non-Sayyid to give his Sadaqa to a Sayyid . If a Sayyid receives Zakat of property or Fitra from a non-Sayyid , it would be forbidden for him to use it, and he who gives it (Zakat), his "Dhimma" (obligation) would not be discharged. In cases other than those mentioned above it is permissible for a non-Sayyid to give his Sadaqa, atonement, or Fidya of fast (Kaffara) or any desirable charity to a Sayyid . Yes, if charity given to a Sayyid is too little an amount of property and it is given with the intention of repulsing calamity and evil, there is Ishkaal (objection) in its being permissible.