COMMENTARY on 17:101
Mustafa Khattab:

Translation:
We surely gave Moses nine clear signs.18 ˹You, O  Prophet, can˺ ask the Children of Israel. When Moses came to them, Pharaoh said to him, “I really think that you, O  Moses, are bewitched.”
Commentary:
18   The nine signs of Moses are: the staff, the hand (both mentioned in 20:17-22), famine, shortage of crops, floods, locusts, lice, frogs, and blood (all mentioned in 7:130-133). These signs came as proofs for Pharaoh and the Egyptians. Otherwise, Moses had some other signs such water gushing out of the rock after he hit it with his staff, and splitting the sea.

 

A. Yusuf Ali:

Translation:
To Moses We did give Nine Clear Sings: 2308 As the Children of Israel: when he came to them, 2309 Pharaoh said to him: "O Moses! I consider you, indeed, to have been worked upon by sorcery! 2310
Commentary:

2308  Nine Clear Signs; see 7:133, n. 1091. The story of Pharaoh (or a phase of it) is here told with a view to exhibiting the decline of a soul on account of pride in outward power and dignity.

2309  To them: i.e., to Pharaoh, as sitting in his Council, with the Chiefs of his People. Cf. 7:103. The whole scene is described in some detail from the point of view of nations or Ummahs in 7:103-133.

2310  At a different and later stage in the scene, Pharaoh's Chiefs call Moses a "sorcerer well-versed" (7:109). Here Moses, who had come with Nine Signs but had not yet shown them, is reproached with being the object of sorcery: he is practically told that he is mad!

 

Muhammad Asad:

Translation:
AND, INDEED, We gave unto Moses nine clear messages. 119 Ask, then, the children of Israel 120 [to tell thee what happened] when he came unto them, [and appealed to Pharaoh, 121 ] and Pharaoh said unto him, "Verily, O Moses, I think that thou art full of sorcery!" 122
Commentary:
119  Some of the commentators assume that this is an allusion to the miracles performed by Moses, while others (relying on a Tradition quoted in the compilations of Nasa'i, Ibn Hanbal, Bayhaqi, Ibn Majah and Tabarani) see in it a reference to nine specific commandments or ethical principles, the foremost of them being a stress on God's oneness and uniqueness. In my opinion, however, the number "nine" may be no more than a metonym for "several", just as the numbers "seven" and "seventy" are often used in classical Arabic to denote "several" or "many"
120  I.e., of the present time. The whole phrase has this meaning: "Ask them about what the Qur'an tells us in this respect, and they will be bound to confirm it on the basis of their own scriptures." This "confirmation" apparently relates to what is said in verse 104, explaining why the story of Moses and Pharaoh has been mentioned in the present context. (The story as such appears in greater detail in 7:103-137 and 20:49-79.)
121  Cf. 7:105-"let the children of Israel go with me!"
122  Or: "that thou art bewitched". However, my rendering is based on Tabari's interpretation of the passive participle mashur, which I consider preferable in view of the subsequent reference to the miraculous signs granted by God to Moses.