20-2-2. Impossible or unlawful condition void. A condition in a contract, the fulfillment of which is impossible or unlawful, within the meaning of chapter 53-5 relating to the object of contracts, or which is repugnant to the nature of the interest created by the contract is void.
Source: CivC 1877, § 811; CL 1887, § 3434; RCivC 1903, § 1127; RC 1919, § 734; SDC 1939, § 47.0111.