'You are Witnesses' in the Bible

Then Boaz said to the elders and to all the people, “You are witnesses this day that I have bought everything that was Elimelech’s and everything that was Chilion’s and Mahlon’s from the hand of Naomi.

I have also acquired Ruth the Moabitess, the widow of Mahlon, to be my wife to restore the name of the deceased to his inheritance, so that the name of the deceased will not be cut off from his brothers or from the gate of his birthplace. You are witnesses today.”