Is it permissible for a wife to return to her husband who divorced her three times after he used to beat and abuse her?

A divorce issued by a husband under duress that is not recognized as valid is void. Duress has conditions: the coercer must be capable, it must be highly probable that the threatened action will occur, and the harm must be significant. Locking the house on the husband is not considered duress. Therefore, his divorce has taken effect. If the husband divorced three times, she becomes irrevocably separated from him (baynunah kubra). If it was less than three times, he can take his wife back before her waiting period (iddah) expires. It is advisable to present the matter to a Sharia court or trusted scholars.