'Truly' in the Bible

If Cain shall be avenged sevenfold, truly Lamech seventy and sevenfold.

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

And the time drew nigh that Israel must die: and he called his son Joseph, and said unto him, If now I have found grace in thy sight, put, I pray thee, thy hand under my thigh, and deal kindly and truly with me; bury me not, I pray thee, in Egypt:

And his father refused, and said, I know it, my son, I know it: he also shall become a people, and he also shall be great: but truly his younger brother shall be greater than he, and his seed shall become a multitude of nations.