'Testify' in the Bible

It shall be, if you shall forget Yahweh your God, and walk after other gods, and serve them, and worship them, I testify against you this day that you shall surely perish.

If an unrighteous witness rise up against any man to testify against him of wrongdoing,

It shall happen, when many evils and troubles are come on them, that this song shall testify before them as a witness; for it shall not be forgotten out of the mouths of their seed: for I know their imagination which they frame this day, before I have brought them into the land which I swore."

He said to them, "Set your heart to all the words which I testify to you this day, which you shall command your children to observe to do, [even] all the words of this law.