"Has He struck him as He struck those who struck him? Or has he been slain as those slain by Him were slain?" (Isaiah 27:7). Rabbi Judah and Rabbi Nehemiah differed. Rabbi Judah said: With the very staff with which the Egyptians struck Israel, they themselves were struck. And Rabbi Nehemiah said: With the very legion-weapon with which the Egyptians struck Israel, they themselves were struck. "In full measure" (ibid. 8) — measure for measure [reading the doubled word as a seah for a seah]. It was taught in the name of Rabbi Meir: By the measure with which a man measures, it is measured back to him. "By driving them out You contend with them" (ibid.) — He smote, and afterward sent away. Therefore it is said, "And it came to pass when Pharaoh let the people go" (Exodus 13:17).
Egypt Struck With the Same Rod It Used on Israel
Pesikta DeRav Kahana 11:4
[ד] הכמכת מכהו הכהו אם כהרג הרוגיו הורג (ישעיה כז:ז). ר' יהוד' ור' נחמיה. ר' יהוד' א' במקל שהכו המצריים את ישר' בו לקו. ור' נחמיה אמ' באיספטי שהכו המצריים את ישר' בה לקו. בסאסאה (שם ח), ביסאה סאה. תני בשם ר' מאיר במידה שאדם מודד בה מודדין לו. בשלחה תריבנה (שם), לקה ואחר כך שילח. לכך נאמ' ויהי בשלח פרעה את העם (שמות יג:יז).