'Testimony to Them' in the Bible

and said to him, See that you say nothing to any one, but go and show yourself to the priest, and offer for your cleansing what Moses commanded, for a testimony to them.

And whatever place will not receive you, nor hear you, when you go out thence shake off the dust which is under your feet for a testimony to them.

But take heed to yourselves; they shall deliver you up to Sanhedrims, and you shall be beaten in synagogues, and shall be brought before governors and kings for my sake, for a testimony to them.