ויושע השם ביום ההוא… (בשלח יד:ל)

The acronym for the word “ההוא” is את השמים ואת הארץ, alluding to the fact that when Hashem created heaven and earth, it was already His will to do good and save the Yidden when they were hemmed in between the desert on their sides, the sea in front of them and the Egyptians closing in from the rear.

ויושע השם – Hashem saved – ביום ההוא – on that day, the day that He created heaven and earth, which is hinted in the word ההוא – because already then it was His will to save.