'Testify' in the Bible

And it shall be, if thou shalt forget Jehovah thy God, and walk after other gods, and serve them, and worship them, I testify against you this day that ye shall surely perish.

If an unrighteous witness rise up against any man to testify against him of wrong-doing,

And it shall come to pass, when many evils and troubles are come upon 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 sware.

And he said unto them, Set your heart unto all the words which I testify unto you this day, which ye shall command your children to observe to do, even all the words of this law.