And in nine signs, the speech is new. The preposition in it relates to something omitted. The meaning is: Go to Pharaoh and the like in nine signs.

I said to the food, so among them ... a group envies humans the food. [[The explanation of this evidence has been presented in the first part, page 2, so refer to it if you wish, may Allah reward the corrector.]]

And it is permissible that the meaning is: And throw down your staff, and put your hand in: in nine signs, meaning: in the total of nine signs and their count. And one might say: The signs were eleven: two of them being the hand and the staff, and the nine are:

the splitting of the sea, the flood, the locusts, the lice, the frogs, the blood, the darkness, the drought in their valleys, and the decrease in their crops.