Rashi: What passed - Ge'ulas Egypt and Chizkiyah's salvation from Sancheriv. I told them before they were, and "suddenly I did them."

Radak: It is the matter of Sancheriv. This rebuke was said after it. Since I told it beforehand via My Nevi'im, and it came, you should have believed in Me and guarded My Mitzvos! You saw that suddenly I did to Sancheriv what I decreed on him - "va'Yetzei Mal'ach Hashem va'Yach b'Machaneh Ashur" (37:36). It says ha'Rishonos, even though it is only one, for he prophesized about it many times in this Sefer.

Malbim: They are miracles that I did when Yisrael deserved miraculous conduct. There was no need for a Navi to predict them before they came.

Rashi: They came like I told beforehand via My Nevi'im.

Malbim: Immediately, when I said to do a miracle, immediately I did it; it came suddenly. When Hashem foretells a miracle via a Navi, first he tells the Navi, and then the Navi tells the nation to publicize it. This was not needed for early miracles; I told and made heard from My mouth ¹ , not via a Navi, and immediately I did it.