(12,23) 1. "Hashem will pass through to smite Egypt, He will see the blood...and Hashem will pass over the entrance and He will not permit the destroyer to enter your homes to smite." But Rashi on (12,12) "Ani Hashem" says, Hashem Himself would carry out the Plague of the Firstborns. And indeed in the Haggadah on "VaYoytzeainu Hashem MiMitzrayim" expounds: 'not through an angel, not through a seraph, not through a messenger, but the Holy One, Blessed is He, in His glory, Himself, as it is stated...' and brings down verse (12,12). So we see that Hashem Himself smote the Egyptians. If so, then why does our verse (12,23) say that Hashem won't let the destroyer enter the Jews' homes? What was the Destroyer doing in Egypt?
(Indeed Ramban to (12,12) renders it "I am Hashem" not like Rashi "I, Hashem". So then the destroyer could have been in Egypt, but what he does with the Haggadah, is beyond me.)