Power irrevocable unless authorized by instrument creating the power

Every power, beneficial or in trust, is irrevocable unless an authority to revoke it is given or reserved in the instrument creating the power. Source: CivC 1877, § 311; CL 1887, § 2827; RCivC 1903, § 334; RC 1919, § 403; SDC 1939, § 59.0416.