Is intention sufficient for the return of a wife divorced once, or is a verbal statement required?

We mentioned in Fatwa (definition) no. 38529 the scholarly disagreement concerning what constitutes a valid return (raj‘ah). The apparent view is that she returns to him simply by virtue of sexual intercourse.

So, if you engaged in intercourse with your wife during her waiting period ('iddah (definition)), this is sufficient for a valid return. However, if you did not return to her verbally or by action until her 'iddah expired, then a new marriage contract, a new dowry, and the guardian's consent are required.