'You are Witnesses' in the Bible

Then Boaz said to the leaders and all the people, "You are witnesses today that I have acquired from Naomi all that belonged to Elimelech, Kilion, and Mahlon.

I have also acquired Ruth the Moabite, the wife of Mahlon, as my wife to raise up a descendant who will inherit his property so the name of the deceased might not disappear from among his relatives and from his village. You are witnesses today."

You are witnesses of these things.

You are witnesses, and so is God, as to how holy and righteous and blameless our conduct was toward you who believe.