2 Chronicles - Chapter 32

Judah is facing an attack from the mighty army of Assyria.  The Israelites are mocked by the King of Assyria:

‘This is what Sennacherib king of Assyria says: on what are you basing your confidence, that you remain in Jerusalem under siege? When Hezekiah says, “The Lord our God will save us from the hand of the king of Assyria,” he is misleading you, to let you die of hunger and thirst."

However, Hezekiah's trust in God is well placed, and God sends one angel, who destroys the whole of the Assyrian army:

"And the Lord sent an angel, who annihilated all the fighting men and the commanders and officers in the camp of the Assyrian king."

In Matthew 26 we read about Jesus being arrested.  Peter takes up a sword to defend him, but Jesus stops any resistance.  Jesus willingly permits his crucifixion.  Having seen in Chronicles what a single angel can do, Jesus knows that he has a whole host of angels ready should he call them:

‘Put your sword back in its place,’ Jesus said to him, ‘for all who draw the sword will die by the sword. Do you think I cannot call on my Father, and he will at once put at my disposal more than twelve legions of angels? But how then would the Scriptures be fulfilled that say it must happen in this way?’