Is it obligatory to observe the iddah now after a divorce whose iddah was not observed at the time?

The waiting period (iddah) for divorce or death begins from the moment the cause occurs, even if the woman is unaware of it. If the woman becomes aware before the iddah ends, she completes the remainder of it. However, if she becomes aware after its expiry, she is not required to make it up, as the iddah was legislated for the purification of the womb and the husband's right to reconciliation, and it has ended with the completion of its term. This is the view of the majority of scholars.