Is Verbal Consent Required for a Valid Nikah?

Assalamun Alaykum, Thank you, I am reaching out because I have a question , and I would be grateful if the resources of the organisation can be used to help clarify the below. Please I have an important on the basis on which an Akhid nikkah is intact. An Akhid nikkah was held, families were introduced, sermon was given, Mary was discussed. However they're was no verbal proclamation of transfer of responsibility from the father of the bride to the Groom. The Groom realises this on the journey home after the gathering and is having doubts about the validity of the nikkah. the groom called the brides father who is an imam and he says there is no need for verbal declaration that the nikkah is valid but the groom is still having doubts kindly clarify with Proof.