'You are Witnesses' in the Bible

Boaz said to the elders and all the people, “You are witnesses today that I am buying from Naomi everything that belonged to Elimelech, Chilion, and Mahlon.

I will also acquire Ruth the Moabitess, Mahlon’s widow, as my wife, to perpetuate the deceased man’s name on his property, so that his name will not disappear among his relatives or from the gate of his home. You are witnesses today.”