Indian Contract Act, 1872
197. Ratification may be expressed or implied
Ratification may be expressed or may be implied in the conduct of the person on whose behalf the acts are done.
(a) A, without authority, buys goods, for B. Afterwards B sells them to C on his own account; B's conduct implies a ratification of the purchase made for him by A.
(b) A, without B's authority, lends B's money to C. Afterwards B accepts interest on the money from C. B's conduct implies a ratification of the loan.