'Add' in the Bible

Which of you by being over-anxious can add a single foot to his height?

And which of you is able by anxious thought to add a moment to his life?

I Paul add with my own hand this final greeting. Be mindful of me in my imprisonment. Grace be with you.

I Paul add the greeting with my own hand, which is the credential in every letter of mine.

"I solemnly declare to every one who hears the words of the prophecy contained in this book, that if any one adds to those words, God will add to him the plagues spoken of in this book;