'Assuredly' in the Bible

Yea, I will rejoice over them to do them good, and I will plant them in this land assuredly with my whole heart and with my whole soul.

Then said Jeremiah unto Zedekiah, Thus saith the LORD, the God of hosts, the God of Israel; If thou wilt assuredly go forth unto the king of Babylon's princes, then thy soul shall live, and this city shall not be burned with fire; and thou shalt live, and thine house:

For thus saith the LORD; Behold, they whose judgment was not to drink of the cup have assuredly drunken; and art thou he that shall altogether go unpunished? thou shalt not go unpunished, but thou shalt surely drink of it.