SDCL § 20-6-3: Want or delay of performance excused by creditor's act inducing nonperformance.

Want of performance, or of an offer of performance, or any delay therein, is excused when the debtor is induced not to make it, by any act of the creditor intended or naturally tending to have that effect, done at or before the time at which such performance or offer may be made, and not rescinded before that time.