Adding something extra to zakaat al-fitr
Question

                Is zakaat al-fitr limited to one saa’ for each member of my family without adding anything extra? What I mean by something extra is adding some charity so as to be on the safe side and make sure that my saa’ is sufficient, without telling the poor person to whom I give it that this is charity. For example, I have ten persons in my family, so I buy a bag of rice weighing fifty kilograms, then I give it all as zakaat al-fitr on behalf of these ten persons, without counting out the saa’s for them, because I know that this is twenty or more kilos extra, intending the extra to be charity, then I do not tell him that this extra is charity, rather I say, “Take our zakaah,” so he does not know that this bag contains more than the zakaah, so he takes it and is happy with it. What is the ruling on that?.
Praise be to Allah.Zakaat al-Fitr is one saa’ of wheat or dates 
    or rice etc., the local staple food, for one person, male ofrfemale, old or young. There is nothing wrong with giving more as zakaat al-fitr as 
    you have done, with the intention of giving charity, even if you do not tell the poor person about it. 
And Allaah is the Source of strength.