ותגעש [וַיִּתְגָּעַ֤שׁ] וַתִּרְעַשׁ֙ הָאָ֔רֶץ מוֹסְד֥וֹת הַשָּׁמַ֖יִם יִרְגָּ֑זוּ וַיִּֽתְגָּעֲשׁ֖וּ כִּֽי־חָ֥רָה לֽוֹ׃
Then the earth did shake and quake, the foundations of heaven did tremble; they were shaken, because He was wroth.
Rashi on II Samuel
Shook and shuddered. This is not referring to the miracles that happened to him but to the miracles that happened to Yisroel and the beginning of the verse is connected to the end.
Rashi on II Samuel
When God became angry. The word כי is being used here to mean "when," and this is its interpretation, when God became angry on account of his antagonists the world shook and shuddered and the pillars of heaven trembled and shook.