VOUCH

[verb] - to be able from your knowledge or experience to prove the truth of something or the honesty and good character of someonePatricia has checked the reports and vouches for the accuracy of the information. [I]As a medical examiner I can vouch from experience that his death was accidental. [+ that clause]He brought along a couple of friends to vouch for him (= to say that he had a good character). [I]