"The burning bush is the Cross. The highest claim of revelation, the 'I am he,' and the Cross of Jesus are inseparably one."

"'When you have lifted up the Son of man, then you will know that I am [(τότε γνώσεσθε ὅτι ἐγω εἰμι)]. . . .'"

Jn 8:28, RSV, but with the concluding pronoun, i.e. "he" ("then you will know that I am he"), removed.  Cf. the LXX of Is 43:10:  "I too am a witness, says the Lord God, and the servant whom I have chosen so that you may know and believe and understand that I am [(ἵνα γνῶτε...ὅτι ἐγώ εἱμι)]" (NETS).  The pronoun is there in the Hebrew of v. 10 ("that I [am] He [(כִּֽי־אֲנִי הוּא)]"), but that is followed by v. 11:  "I, I am the Lord [(אָנֹכִי אָנֹכִי יְהוָה, ἐγὼ ὁ Θεός)]".  All of this is brought out on pp. 347-349 (pp. 345 ff.) of Joseph Ratzinger's Jesus of Nazareth: from the baptism in the Jordan to the transfiguration, trans. Adrian J. Walker (New York, NY:  Doubleday, 2007), whence the heading, which occurs on p. 349.