Iqbal Ahmad, J.
1. This is a plaintiff's appeal and arises out of a suit for sale on a mortgage dated 22nd October 1908.
2. The suit was resisted, inter alia, on the ground, that it was time barred. Both the Courts below gave effect to this contention and dismissed the suit.
3. According to the terms of the mortgage-deed the stipulated time for payment of the principal and interest was three years and interest was payable half yearly and in case of default it was to be added to the principal and interest, at the agreed rate, was to be charged on that amount. The Courts below held that, in view of the terms of the bond, the cause of action for recovery of the mortgage debt accrued on default of the mortgagor to pay interest on the expiry of six months from the date of the mortgage-deed and as the plaintiffs did not put the mortgage into suit within a period of 12 years from that date, the suit was time barred. In so construing the mortgage deed in suit the Courts below placed reliance on an unreported decision of this Court in Second Appeal No. 1178 of 1921, decided on 9th June 1922.
4. I am unable to agree with the Courts below. The relevant words in the mortgage-deed in suit, on the interpretation of which the decision of this case must turn, are these:
iqrar yeh hai ke rupya mazkura bala mai sud ba hisab tin rupya do anna mahwari ke arsa tin sal men ada wa bebak karunga, xur sud uska har shashmahi ada harunga, jis shashmahi per zar sud ada na karun to raqam sun shamil asal ke hohar usper bhi sud ba sharah mazkura bala ada karunga, dar surat wada khilafi ke murtahin ko ikhtiar hoga ke kul rupya apana yakmusht mai sud wa balai sud bazarie adalat, mujh se was sahai marhuna wa niz zat wa digar jaiddd meri se wasul karlewe
5. The Courts below were of opinion that the words 'wada khilafi' in the passage quoted above, have reference, not only to the default of mortgagor to pay the mortgage money on the expiry of three years but also, to his default to pay interest on the expiry of six months from the date of the mortgagee-deed and, therefore, time began to run against the mortgagee on the failure of the mortgagor to pay interest on the expiry of six months from the date of the mortgage. The interpretation put upon the passage quoted above, by the Courts below does not commend itself to me.
6. The mortgagor agreed to pay interest every six months and in case of failure to pay interest for six months, he agreed to pay compound interest. So far as the payment of interest was concerned, the mortgagor agreed that, in case of his default to pay interest on the expiry of six months, the remedy of the mortgages would be to add the same to the principal and thus charge compound interest. The stipulation as to payment of interest ends there and proceeds no further. In case of breach of covenant (dar surat wada khilafi) the mortgagee is authorized to recover, by suit, not only simple interest but compound interest as well. It is also manifest that if default in payment of interest on the expiry of six months entitle the mortgagee to sue at once and he did so sue, he would not be entitled to get compound interest. The words 'dar surat wada khilafi' therefore, can have reference only to the default in payment at the end of the stipulated period of three years. The 'ekrar' to pay in three years is the 'wada' and the 'wada khilafi' is the default in the performance of that 'ekrar.' No doubt the mortgagor also covenanted to pay interest every six months, but in the mortgage-deed there is no covenant to the effect that in default of payment of Interest the mortgagee will be entitled either to add the same to the principal and charge interest on the consolidated amount or to put the mortgage in suit. If it was intended that in default of payment of interest the mortgagee would be entitled to sue, without waiting for the stipulated period of three years, I would expect clear language to that effect in the deed. Bat the deed is conspicuous by an absence of any such language. In every case in which there is a stipulation to pay compound interest, there must be a provision to pay interest at stated intervals, otherwise the payment of compound interest with prescribed rests cannot be provided for. In such cases the promise is to pay simple interest and to pay compound interest on default of payment of simple interest. The promise is one and indivisible and, the mere nonpayment of simple interest does not constitute a breach of the promise.
7. It is worthy of note that in the mortgage-deeds that formed the subject matter of consideration, in the Full Bench decisions of Gaya Din v. Jhumman, Lal  37 All. 400 and Shib Dayal v. Meharban A.I.R. 1923 All. 1, in which it was held that, on default of payment of interest, time began to run against the mortgagee, there were clear provisions in each deed that, on default being made by mortgagor to pay interest the mortgagee would be entitled either to add the same to the principal and charge compound interest, or without waiting for the stipulated period to put the mortgage-deed into suit. There was a similar provision in the mortgage-deed that formed the subject matter of decision in Ram Das v. Mohammad Said Khan A.I.R. 1922 All. 524. I am not aware of any case decided by this Court, except the case to which reference has been made by the Courts below, in which, in the absence of a clear provision in the mortgage-deed, empowering the mortgagee in the event of default in payment of interest, to sue for the mortgage debt, without waiting for the period provided by the deed for payment of that debt, it was held that cause of action for recovery of the mortgage debt accrued to the mortgagee on default of payment of interest. In Second Appeal No. 1178 of 1921, the mortgage bond contained the following stipulations:
Ba iqrar adai sud fi sadi ke rupya char anna mahwari qarz leya, iqrar jeb hai ke mubligan mazkur wada chah sal men ada kardenge magar sud sal ba sal ada karte rahenge, dar surat adam adai zar sud salana ke sud naga shuda shamil zar asal hoga, aur usper bhi sud bashareh sadar ada karenge, dar surat wada, khilafi daen ko ikhtiar hoga ke sab rupya apna mai sud wa balai sud fistrah mumkin ho ham se wa niz jaidad mustagharqa tahat wa digar jaidad manqula wa ghair manqula hamari se yakmusht wasul karlewe, hamko our warisan hamare ko kuch uzr kisi qisam ka na hoga
and two learned Judges of this Court held that the words 'dar surat wada khilafi.' governed both the promise to pay interest at the end of each year and the promise to pay the mortgage debt in six years and, therefore, they came to the conclusion that the case was governed by the Full Bench decision of Gaya Din v. Jhumman Lal A.I.R. 1923 All. 1. No reasons for putting this interpretation are given in the judgment, and, with all respect, I am unable to agree with that decision. Further it is well settled that it is not permissible to interpret one document by the language of another, specially where the languages, though similar, are not identical.
8. As the suit was decided by the lower appellate Court on a preliminary point and, I am not in agreement with the decision of that Court, I would allow this appeal, set aside the decree of the lower appellate Court and remand the case to that Court with directions to readmit the appeal to its original number and dispose it of according to law.
9. Costs here and hitherto should be costs in the cause and must abide the result.
10. I have read the judgment of my learned brother and I regret that I cannot agree that the interpretation of the bond in suit is free from doubt. The portion quoted in vernacular lays down the following four provisions:
(1) It is agreed that I shall repay principal and interest at Rs. 3-2-0 p.m. in the period of three years.
(2) And that I shall pay the interest every six months.
(3) Any six-monthly interest unpaid will be added to the principal and I shall pay interest at the above rate on it.
(4) In case of breach of covenant the mortgagee may realise from me all the principal at once with interest and compound interest through the Court, etc.
11. It appears to me that the provision (4) for breach of covenant may either be read as applying to both the covenants (1) and (2), or as applying to (1) only. It may be said in favour of applying it to both that it comes after both. It may be said in favour of applying it to (1) only that there is already a provision (3) for breach of (2). It would have been quite easy to add a few words to (4) to show whether it applied to (1) and (2) or to (1) only. In the absence of those few words I consider that the Clause (4) is ambiguous.
12. In favour of applying (4) to (2) it was also argued that as (1) provided for repayment of principal and interest in the period of three years it was open to the mortgagee to sue on a breach of that covenant without any special provision for suing: but that if the mortgagee was to have a right to sue on the failure to pay any six-monthly interest, then a special provision was necessary for that purpose.
13. The view that I take that the provision is ambiguous is further supported by the fact that two learned Judges of this Court in Second Appeal No. 1178 of 1921 where a deed with practically similar provisions was produced, held that (4) applied to both (1) and (2), and that there could be no doubt whatever on the subject. This is also the view of the two lower Courts in the present case.
14. My learned brother, however, takes the opposite view, which was the view taken by the lower appellate Court in the Second Appeal No. 1178 of 1921.
15. I hold that the provisions in the mortgage deed on the point are ambiguous. Under Section 93, Evidence Act, evidence may not be produced to show what was the meaning of the parties. The clause therefore remains ineffectual, so far as its application to the interest is concerned. The defendant bases his plea of limitation on this clause, alleging that owing to a breach of the covenant for the payment of interest the cause of action arose more than twelve years before the date of suit. Under Section 103, Evidence Act, the burden of proof that this was a term of the contract lay on the defendant. The defendant has failed to discharge that burden of proof. His plea of limitation therefore fails. The lower appellate Court has dismissed the appeal of the plaintiff on the ground of limitation only. Accordingly the decree of the lower appellate Court should be set aside and the appeal remanded for disposal.