Daniel 10:18 (KJV)

But the prince of the kingdom of Persia withstood me one and twenty days: but, lo, Michael, one of the chief princes, came to help me; and I remained there with the kings of Persia.

Now I am come to make thee understand what shall befall thy people in the latter days: for yet the vision is for many days.

And when he had spoken such words unto me, I set my face toward the ground, and I became dumb.

And, behold, one like the similitude of the sons of men touched my lips: then I opened my mouth, and spake, and said unto him that stood before me, O my lord, by the vision my sorrows are turned upon me, and I have retained no strength.

For how can the servant of this my lord talk with this my lord? for as for me, straightway there remained no strength in me, neither is there breath left in me.

And said, O man greatly beloved, fear not: peace be unto thee, be strong, yea, be strong. And when he had spoken unto me, I was strengthened, and said, Let my lord speak; for thou hast strengthened me.

Then said he, Knowest thou wherefore I come unto thee? and now will I return to fight with the prince of Persia: and when I am gone forth, lo, the prince of Grecia shall come.

But I will shew thee that which is noted in the scripture of truth: and there is none that holdeth with me in these things, but Michael your prince.