'Testify' in the Bible

To whom shall I speak and testify, that they may hear? Behold, their ear is uncircumcised, and they can't listen. Behold, the word of Yahweh has become a reproach to them. They have no delight in it.

Though our iniquities testify against us, work for your name's sake, Yahweh; for our backslidings are many; we have sinned against you.