law: Indian Divorce Act, 1869 
  37. Power to order permanent alimony 
  The High Court, may, if it thinks fit, on any decree absolute
  
  declaring a marriage to be dissolved, or on any decree of judicial separation
  
  obtained by the wife, and the District Judge may, if he thinks fit, on the
  
  confirmation of any decree of his declaring a marriage to be dissolved, or on
  
  any decree of judicial separation obtained by the wife,
  order that the husband shall, to the satisfaction of the Court,
  
  secure to the wife such gross sum of money, or such annual sum of money for any
  
  term not exceeding her own life, as, having regard to her fortune (if any), to
  
  the ability of the husband, and to the conduct of the parties, it thinks
  
  reasonable; and for that purpose may cause a proper instrument to be executed
  
  by all necessary parties.
   Power to order monthly or weekly payments-  In every such case
  
  the court may make an order on the husband for payment to the wife of such
  
  monthly or weekly sums for her maintenance and support as the court may think
  
  reasonable:
  PROVIDED  that if the husband afterwards from any cause
  
  becomes unable to make such payments, it shall be lawful for the court to
  
  discharge or modify the order, or temporarily to suspend the same as to the
  
  whole or any part of the money so ordered to be paid, and again to revive the
  
  same order wholly or in part as to the court seems fit.