400.2-609. (1) A contract for sale imposes an obligation oneach party that the other's expectation of receiving dueperformance will not be impaired. When reasonable grounds forinsecurity arise with respect to the performance of either partythe other may in writing demand adequate assurance of dueperformance and until he receives such assurance may ifcommercially reasonable suspend any performance for which he hasnot already received the agreed return.
(2) Between merchants the reasonableness of grounds forinsecurity and the adequacy of any assurance offered shall bedetermined according to commercial standards.
(3) Acceptance of any improper delivery or payment does notprejudice the aggrieved party's right to demand adequateassurance of future performance.
(4) After receipt of a justified demand failure to providewithin a reasonable time not exceeding thirty days such assuranceof due performance as is adequate under the circumstances of theparticular case is a repudiation of the contract.
(L. 1963 p. 503 ยง 2-609)