Which of the two contracts is valid: the first with a dowry of five hundred Iraqi dinars, or the second with a deferred dowry of nineteen mithqals of gold? And how much debt do I owe my wife?

If the first marriage contract was valid and met all conditions, then the recognized mahr (dowry) is what was stipulated in it (500 dinars), and the second contract has no effect. As for the increase agreed upon in the second contract:

1. If you agreed to it thinking it was binding due to the new contract, then it is not binding, and you can reclaim it if you have paid it.

2. If you knew it was not binding but paid it with the intention that it be part of the mahr, then it is binding upon you, because an increase in the mahr after the contract becomes binding upon the husband.