'Surely' in the Bible

And if Satan has risen up against himself and is divided, he cannot stand, but is coming to an end.

For Moses said, ‘Honor your father and your mother [with respect and gratitude]’; and, ‘He who speaks evil of his father or mother must be put to death’;

Calling His disciples to Him, He said to them, “I assure you and most solemnly say to you, this poor widow put in [proportionally] more than all the contributors to the treasury.

I assure you and most solemnly say to you, this generation [the people living when these signs and events begin] will not pass away until all these things take place.

I assure you and most solemnly say to you, wherever the good news [regarding salvation] is proclaimed throughout the world, what she has done will be told in memory of her.”

While they were reclining at the table, Jesus said, “I assure you and most solemnly say to 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.”