give (one's) stamp of approval

To give an official indication of one's endorsement, authorization, or approval (of someone or something). A noun or pronoun can be used after "give" to specify what is being authorized or endorsed. No, you can't start that construction project until the boss gives it his stamp of approval. I'm ready to hire someone for the marketing position—after you give your stamp of approval, that is. Are you really sure you want to give these unfounded claims your stamp of approval? If they're proven false, your reputation will be ruined.