law: Indian Contract Act, 1872 
  40. Person by whom promise is to be
  
  performed
  If it appears from the nature of the case that it was the
  
  intention of the parties to any contract that any promise contain in it should
  
  be performed by the promisor himself, such promise must be performed by the
  
  promisor. In other cases, the promisor or his representatives may employ a
  
  competent person to perform it.
   Illustrations 
  (a) A promises to pay B a sum of money. A may perform this
  
  promise, either by personally paying the money to B, or by causing it to be
  
  paid to B by another; and, if A dies before the time appointed for payment, his
  
  representatives must perform the promise, or employ some proper person to do
  
  so.
  (b) A promises to paint a picture of B. A must perform this
  
  promise personally.