'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 near that Israel must die: and he called his son Joseph, and said unto him, If now I have found favor 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;