What is the ruling on a husband taking back his wife and consummating the marriage after her 'iddah (waiting period) has expired, out of ignorance and without a new contract, knowing that she was returned to the home two years after her divorce, and he consummated the marriage on the first day, and on the second day she was sent back to her family, then a new contract was made with a new mahr (dowry), and she stayed for three years then they separated?

The رجعة (reconciliation/taking back) of the wife after the expiry of her 'iddah (waiting period) following an irrevocable divorce (طلاق بائن) is invalid. If a marriage contract is then concluded with her, it is valid, provided the husband has not yet completed three divorces. Some scholars hold that istibra' (ensuring the womb is clear of pregnancy) is obligatory before the marriage contract. If the contract is concluded after the womb has been cleared, it is valid. Otherwise, the contract is not valid according to the Malikis and Hanbalis, while it is valid according to the Hanafis and Shafi'is.