'Confirming' in the Bible

"Ask for a confirming sign from the Lord your God. You can even ask for something miraculous."

For this reason the sovereign master himself will give you a confirming sign. Look, this young woman is about to conceive and will give birth to a son. You, young woman, will name him Immanuel.

Isaiah replied, "This is your sign from the Lord confirming that the Lord will do what he has said:

Hezekiah said, "What is the confirming sign that I will go up to the Lord's temple?"

Confirming the word of His servant, The counsel of His messengers it perfecteth, Who is saying of Jerusalem, She is inhabited, And of cities of Judah, They shall be built, and her wastes I raise up,