'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.

For thus saith Jehovah: Behold, they to whom it pertained not to drink of the cup shall assuredly drink; and art thou he that shall altogether go unpunished? thou shalt not go unpunished, but thou shalt surely drink.