Parashas Beshalach · Passuk 14:7
Chabad.org — English translation + Rashi
Torah Temimah points to Pesachim 118b (verified).
English: Rabbah bar Mari expounded: What is meant by “And they rebelled at the sea, at Yam Suf”? It teaches that Yisrael rebelled at that moment and said: Just as we are ascending from one side, so the Egyptians are ascending from the other side. The Holy One, blessed be He, said to the prince of the sea: Spew them onto the dry land… I will give you one and a half times their number — for concerning Pharaoh it is written “six hundred chariots,” and concerning Sisera it is written “nine hundred chariots.”
On the daf / in context: See the cited source for the full section.
Derash on the verse.
The six hundred chariots of Pharaoh became the measure by which the sea was later compensated with Sisera’s nine hundred.