'Assuredly' in the Bible

It happened in those days, that the Philistines gathered their armies together for warfare, to fight with Israel. Achish said to David, "Know assuredly that you shall go out with me in the army, you and your men."

Go in to king David, and tell him, 'Didn't you, my lord, king, swear to your handmaid, saying, Assuredly Solomon your son shall reign after me, and he shall sit on my throne? Why then does Adonijah reign?'

She said to him, "My lord, you swore by Yahweh your God to your handmaid, 'Assuredly Solomon your son shall reign after me, and he shall sit on my throne.'

most certainly as I swore to you by Yahweh, the God of Israel, saying, 'Assuredly Solomon your son shall reign after me, and he shall sit on my throne in my place;' most certainly so will I do this day."

Yes, 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.

Again, assuredly I tell you, that if two of you will agree on earth concerning anything that they will ask, it will be done for them by my Father who is in heaven.

Whoever will not receive you nor hear you, as you depart from there, shake off the dust that is under your feet for a testimony against them. Assuredly, I tell you, it will be more tolerable for Sodom and Gomorrah in the day of judgment than for that city!"

Jesus said to him, "Assuredly I tell you, today you will be with me in Paradise."

or does he say it assuredly for our sake? Yes, it was written for our sake, because he who plows ought to plow in hope, and he who threshes in hope should partake of his hope.