What is the significance of the word "b'cha"?
Rashi and Targum Yonasan: It teaches us that the frogs actually entered their stomachs and proceeded to croak inside them.
Why did Hashem send a plague of frogs on the Egyptians.*
Oznayim la'Torah: The sound of the myriads of frogs' incessant croaking was deafening
Oznayim laa'Torah: As Hashem said to Kayin