Commentary for Exodus 8:7

וסרו הצפרדעים, G’d will not only remove the ones which have already bothered you, but He will ensure that they will not again afflict you.

V. 7. מלרו ,וסרו gegen die Regel der עוי, die nur sehr seltene Ausnahmen hat. מלרע wäre die Wurzel סרה und nicht סרה .סור heißt chaldäisch: faul werden. Im Hebräischen heißt nicht סרה, wohl aber סרח faul werden. Es kann sein, dass es heiße, nicht: sie werden zurückkehren, sondern: sie werden wegfaulen.

ממך ומבתיך, but not from the whole country; on the contrary, they will die in the land and cause a stench, but in the future they will not leave their habitat in or near the river.

“By tomorrow.” This can be explained according to the Zohar that states that witchcraft can be performed only from midday until midnight, but not in the morning. Pharaoh suspected Moshe of using witchcraft, and so when Moshe asked, “Exactly for when shall I pray for you?” he answered, “Tomorrow morning,” when it is impossible to do witchcraft. At the time they were together, however, it was after midday and he suspected that Moshe would use witchcraft.