Brachot 6a

R. Abin son of R. Ada in the name of R. Isaac says [further]: How do you know that the Holy One, blessed be He, puts on tefillin?

For it is said: The Lord has sworn by His right hand, and by the arm of His strength.

‘By His right hand': this is the Torah; for it is said: At His right hand was a fiery law unto them.

‘And by the arm of his strength:' this is the tefillin; as it is said: The Lord will give strength unto His people."

And how do you know that the tefillin are a strength to Israel?

For it is written: And all the peoples of the earth shall see that the name of the Lord is called upon you, and they shall be afraid of you, and it has been taught: R. Eliezer the Great says: This refers to the tefillin of the head.

R. Nahman b. Isaac said to R. Hiyya b. Abin: What is written in the tefillin of the Lord of the Universe?

He replied to him:"And who is like your people Israel, a nation one in the earth."

Does, then, the Holy One, blessed be He, sing the praises of Israel?

Yes, for it is written: You have affirmed the Lord this day . . . and the Lord has affirmed you this day.

The Holy One, blessed be He, said to Israel: You have made me a unique entity in the world, and I shall make you a unique entity in the world.

You have made me a unique entity in the world,' as it is said: Hear, O Israel, the Lord our God, the Lord is one.

‘And I shall make you a unique entity in the world,' as it is said: And who is like Your people Israel, a nation one in the earth.

R. Aha b. Raba said to R. Ashi: This accounts for one case (of God's tefillin), what about the other cases?

He replied to him: [They contain the following verses]: For what great nation is there, etc.; And what great nation is there, etc.; Happy are you, O Israel, etc.; Or has God assayed, etc.; and To make you high above all nations.

If so, there would be too many cases?

Hence [you must say]: For what great nation is there, and And what great nation is there, which are similar, are in one case; Happy are you, O Israel, and Who is like your people, in one case; Or has God assayed, in one case; and To make you high, in one case.

"And I will take away My hand, and you will see My back." R. Hama b. Bizana said in the name of R. Simon the Pious: This teaches us that the Holy One, blessed be He, showed Moses the knot of the tefillin.