SEIF 10 (Cont.)
The Magen Avraham in the name of the Mateh Moshe says that if one forgets to say Vayechulu by Kiddush, when he remembers he should say it over a cup of wine even in the middle of the meal. The Elya Rabbah says that he researched the Mateh Moshe but could not find any reference to him saying such a Halacha. The Rokeach says the entire reason for saying Vayechulu during Kiddush is in case it was forgotten during Davening. Therefore, if it was said during Davening, why must someone bring another cup just to fulfill the backup?