'Truly' in the Bible

But she is also truly my sister, the daughter of my father, but not the daughter of my mother; and she became my wife.

And now, if ye will deal kindly and truly with my master, tell me; and if not, tell me; and I will turn to the right hand or to the left.

And the days of Israel approached that he should die. And he called his son Joseph, and said to him, If now I have found favour in thine eyes, put, I pray thee, thy hand under my thigh, and deal kindly and truly with me: bury me not, I pray thee, in Egypt;

But his father refused and said, I know, my son, I know: he also will become a people, and he also will be great; but truly his younger brother will be greater than he; and his seed will become the fulness of nations.