'Testimony' in the Bible

and saith unto him, See thou say nothing to any man: but go show thyself to the priest, and offer for thy cleansing the things which Moses commanded, for a testimony unto them.

And whatsoever place shall not receive you, and they hear you not, as ye go forth thence, shake off the dust that is under your feet for a testimony unto them.

But take ye heed to yourselves: for they shall deliver you up to councils; and in synagogues shall ye be beaten; and before governors and kings shall ye stand for my sake, for a testimony unto them.