'Solemnly' in the Bible

“I assure you and most solemnly say to you, all sins will be forgiven the sons of men, and all the abusive and blasphemous things they say;

and screaming with a loud voice, he said, “What business do we have in common with each other, Jesus, Son of the Most High God? I implore you by God [swear to me], do not torment me!”

And Jesus said to them, “I assure you and most solemnly say to you, there are some of those who are standing here who will not taste (experience) death before they see the kingdom of God after it has come with power.”

and whoever gives you a cup of water to drink because you belong to Christ, I solemnly tell you that he will certainly not lose his reward.

And I solemnly tell you that wherever in the whole world the Good News shall be proclaimed, this which she has done shall also be told in remembrance of her."

And while they were at table Jesus said, "I solemnly tell you that one of you will betray me--one who is eating with me."

I assure you and most solemnly say to you, I will not drink again of the fruit of the vine until that day when I drink it new in the kingdom of God.”

"I solemnly tell you," replied Jesus, "that to-day--this night--before the cock crows twice, you yourself will three times disown me."