Is it permissible to give the wife a portion of her deferred dower for matters on which the husband is not obligated to spend?

It is permissible for the husband to consider what he pays to his wife, in excess of her obligatory maintenance, as part of her deferred mahr (dowry), and he should inform her of this. If they dispute:

If the dispute is concerning the intention of the payment (whether it was a gift or mahr), then the husband's word is accepted without an oath, as he knows his own intention best.

If the dispute is concerning the wording of the payment (whether he said it was a gift or denied it), then the husband's word is accepted with his oath.

If what was paid is not of the same type as the agreed-upon mahr, and the husband claims it is from the mahr, then the wife has the right to return what he gave her and demand her original mahr.

If the husband claims it is from her mahr and she claims it is a gift, then each of them should swear an oath, and they should retract what each is claiming.