On Rehearing.
HAWTHORNE, Judge.A rehearing was granted to review the correctness of our decision insofar as it reversed the judgment of the Court of Appeal awarding interest to Charles X. Miller on his demand against Pittman for the retainage held by Pittman under the terms of their contracts. The Court of Appeal -had held that any interest due to •Charles ■ X. Miller should begin to run 10 •days after final payment was received by Pittman Construction Company from the Housing Authority of New Orleans.1 The basis of this holding was Article XI of the subcontract between Pittman and Miller which “imposes an obligation of making final payment on the subcontract within 10 days after (1) completion of the work, (2) acceptance by the architect, and (3) full payment for the work by the owner. The contract is not ambiguous and its simple effect is to make payment by the owner to the prime contractor a suspensive condition to the prime contractor’s obligation to make payment to its subcontractor. * * * In view of the foregoing conclusion, interest shall only begin to run in favor of Miller ten days after the Housing Authority has made final payment to Pittman.” See 175 So.2d 326, at p. 331.
This court reversed the judgment of the Court of Appeal as follows:
"1. Insofar as it denied Charles X. Miller interest from judicial demand on the $41,001.52 retained by Pittman Construction Company under the terms of their contracts, it is reversed; and, it is now ordered, adjudged and decreed that the judgment be amended by granting Miller legal interest on the amount retained ($41,001.52) by Pittman Construction Company from judicial demand until paid.”
.The basis of this reversal of the Court of Appeal judgment was a concession made by Pittman in its brief in that court as follows:
*637“ Tn the case of Pittman Construction Company v. The Housing Authority of New Orleans, [La.App.] 169 So.2d 122 * * *, this Court (Fourth Circuit Court of Appeal) held that Pittman was entitled to recover from HANO legal interest on the retainage which had been due the prime contractor since June 10, 1955.
“ 'If that judgment in favor of Pittman for interest on its retainage were to remain effective, and Pittman were to receive from HANO payment of that interest, Pittman zvould have no objection to the district court’s aivard of interest to Miller. However, HANO’s petition for writs is pending before the Supreme Court, and even the award of interest to Pittman is not now conclusive.’ (Emphasis supplied.)2
“We therefore conclude the Court of Appeal erred in denying Miller legal interest on the entire amount retained by Pittman from judicial demand.”
On application for rehearing Pittman pointed out that an examination of the district court’s award of interest to Miller, which was the basis of its concession, would show that this court enlarged and -extended the concession beyond its actual meaning and significance. The district court’s award of interest was not on the whole retainage by Pittman from Miller, but wáson the sum resulting after deduction from that retainage of certain items which it found Pittman was entitled to withhold from the final payment to Muller. ' That judgment insofar as pertinent read:
“IT IS ORDERED, ADJUDGED AND DECREED, that Charles X. Miller recover from Pittman Construction Company * * * the sum of $41,001.52, less the following:
“V- — A sum sufficient to satisfy and discharge the levy served'by the United States Government on Pittman Construction Company for taxes, penalties and interest owed the United States by Charles X. Miiler * * * ■
“2 — The amount paid or payable by Pittman Construction Company to satisfy the judgment rendered in favor of August A. Wegmann, Receiver of J. J. Clarke Co., Inc.; and
“3 — The sum of $4,139.28 necessary to satisfy and discharge the lien filed by Schwartz Supply Company, Inc., which sum shall be paid to Schwartz Supply Company, Inc., and/or its assignee;3
“together with legal interest on the resulting net amount from September 9,, 1955 [date of judicial demand], until paid,. *639and all costs of Charles X. Miller herein.” (Italics ours.)
It is clear, therefore, that Pittman is correct in its contention that this court enlarged its concession because that concession contemplated only the interest award of the district court and that court awarded interest not on $41,001.52, but on $41,001.52 less the items deducted. Except for this concession of Pittman the Court of Appeal’s award of interest according to the terms of the contract as to payment would be correct, but Pittman reaffirms in this court that it is willing to have interest run from judicial demand on the net amount of the district court judgment, and we shall render judgment accordingly.
Miller and Maryland Casualty have attempted to sustain the judgment of this court for interest on the whole retainage of $41,001.52 from date of judicial demand on grounds of unjust enrichment, equitable estoppel, and the argument that a debt may become due before it becomes payable and in that case interest runs from the time it becomes due rather than from the time it becomes payable. We do not regard any of these as persuasive.
The unjust enrichment argument stems from Pittman’s recovery of interest from 1955 on the whole retainage in its judgment against HANO. Miller argues that Pittman will be unjustly enriched at his expense unless he likewise recovers interest on his whole retainage from the date of his judicial demand in 1955. An unjust enrichment argument cannot prevail in a case such as this where we have concluded that the contract between the parties established when the delay would commence in Pittman’s performance of its obligation to pay Miller — 10 days after Pittman received payment from HANO. See Civil Code art. 1935. Our Code makes it clear that tha equitable doctrine of unjust enrichment can apply only when the parties have not contracted in regard to a matter. Otherwise the contract is the law between them. Civil Code arts. 1963-1965. There can be no justification, therefore, for our saying that the delay commenced in Pittman’s performance of its obligation to pay Miller from the date of judicial demand. Hence Pittman cannot be regarded as enriching itself at Miller’s expense.
Counsel fail completely to show how equitable estoppel can apply in this case so as to make binding as to Miller concessions made by Pittmann regarding interest in other litigation as to other subcontractors. They cite Keller v. Thompson (La.App. 1961), 134 So.2d 395, for the proposition that the concession made by Pittman as to the other subcontractors in other litigation ought to be persuasive here. True, the Keller case stands for the proposition that a question of law decided by an appellate court in one case is persuasive in other cases where the identical question is presented. *641That case, however, could have no application to the issue here where, as demonstrated above, Pittman’s concession was clearly limited as to Miller.
We are not impressed with the argument that under the authority of Consolidated Association Bank v. Foucher (1836), 9 La. 476, the final payment to Miller became due and interest began to run before it became payable. That case has no application to this one. We are now convinced, as was the Court of Appeal, that the provision making final payment to Miller conditioned upon Pittman’s receiving its payment from HANO protected Pittman from being obligated to pay interest in the event the final payment was withheld by HANO.
For the reasons assigned the judgment of the Court of Appeal relating to interest due Miller is set aside, and the judgment of the district court insofar as it awarded to Miller “legal interest on the resulting net amount from September 9, 19SS, until paid” is reinstated and made the judgment of this court. All costs in this court in the proceedings relating to interest on the judgment in favor of Miller are to be paid by Charles X. Miller and Maryland Casualty Company.
FOURNET, C. J., dissents and assigns written reasons. HAMITER, J., dissents, he being of the opinion that the judgment rendered by this court on the original hearing was correct and should be reinstated.ON REHEARING
. HANO paid Pittman on March 32, 1965.
. Certiorari was denied by this court on February 5, 1965, and the recovery of interest by Pittman became final. See La.App., 169 So.2d 122.
. These deductions resulted from liens and claims against Miller in cmlnection with . the contract work caused by Miller’s de- . fault which Pittman became obligated to-pay. ' '