Liturgy zu Schemot 8:30

Rabbi Yose Hagelili says, "From where can you [derive] that the Egyptians were struck with ten plagues in Egypt and struck with fifty plagues at the Sea? In Egypt, what does it state? 'Then the magicians said unto Pharaoh: ‘This is the finger of God' (Exodus 8:15). And at the Sea, what does it state? 'And Israel saw the Lord's great hand that he used upon the Egyptians, and the people feared the Lord; and they believed in the Lord, and in Moshe, His servant' (Exodus 14:31). How many were they struck with with the finger? Ten plagues. You can say from here that in Egypt, they were struck with ten plagues and at the Sea, they were struck with fifty plagues."