'Add' in the Bible

And who of you by being worried can add a single hour to his life?

And which of you by worrying can add a single hour to his life’s span?

Another angel came and stood at the altar, holding a golden censer; and much incense was given to him, so that he might add it to the prayers of all the saints on the golden altar which was before the throne.

I testify to everyone who hears the words of the prophecy of this book: if anyone adds to them, God will add to him the plagues which are written in this book;