2427. In a marriage, be it temporary or permanent, a formal expression must be pronounced. The mere consent of the man and the woman will not suffice. The formal expression may be pronounced by the man and the woman themselves, or they may deputize a third party to pronounce it on their behalf.
2428. The deputy does not have to be a man. A woman may also be a deputy on behalf of a party to pronounce the formal expression of the marriage.
2249. As long as the man and woman are not certain or confident that their deputy has pronounced the formal expression, they may not sanction the consequences and precepts of the marriage. Merely speculating that the deputy has pronounced the formal expression will not suffice. If the deputy states that he has pronounced it, then in the event that he is trustworthy and one does not entertain a doubt that is contrary to his claims, it will suffice. The same applies if one acquires confidence in his statement. In other than the two aforementioned cases, it is problematic to rely solely on the statement of the deputy.
2430. If a woman deputizes someone to marry her to a man for ten days, but does not specify a start date for the ten day period, the deputy can marry her to the man for ten days commencing from whenever he wishes. However if it is known that the woman has intended a particular date or time, the deputy must pronounce the formal expression according to her intention.
2431. A (single) person may be deputized on behalf of both parties to pronounce the formal expression of the marriage contract, be it a temporary one or a permanent one. In fact, a man may be deputized by a woman to marry her to himself, both in a temporary marriage or a permanent one.
The recommended precaution however is that the formal expression should be pronounced by two individuals, especially in the event that a person is deputized to marry someone to himself.