53:1 Witness are the Stars that set along a course appointed. [They never misguide you. He Who commands them, commands the Messenger 6:98, 56:75. Wa = And = Consider = Witness = For = By. Najm is singular as well as plural in the form of a galaxy]
53:2 Your honored companion is neither in error, nor is he misled.
53:3 Nor does he utter the Word out of his desire.
53:4 This (Qur’an) is but a revelation that is being revealed to him.
53:5 He has been taught by the One Mighty in Powers.
I repeat, the above does not say he had other none Quranic revelation, or that these relate to his telling others he had received revelation. It is obvious he told everyone he had received revelation, but what he was repeating to them was the revelation, the Quran, and other than the Quran he had no revelation.
There is no verse in the Quran stating that Allah revealed the Quran and something else, so we cannot accept anything other than the Quran.
5:44 We did send down the Torah containing guidance and a light. By it the Prophets who always sincerely submitted to God, judged the Jews. And the rabbis and the priests judged according to God’s scripture as they were commanded to observe. To them was entrusted the protection of God’s Book, and they were witnesses to it. So, fear not people, but fear Me and do not trade away My revelations for petty gains. And whoever fails to judge or rule by what God has revealed, such are the disbelievers (‘Kafiroon’).
5:45 For them (Jews), We had decreed in the Torah: Life for life, eye for eye, nose for nose, ear for ear, tooth for tooth, and equal injury for injury. But if one forgoes retaliation by way of charity, it will absolve his imperfections. And whoever fails to judge or rule by what God has revealed, such are wrongdoers (‘Zalimoon’). [Exodus 21:23. That was a Mosaic law specific to the Israelites. The Final revelation of God, the Qur’an has updated laws for all humanity for all times. Incidentally, Exodus in the Bible as seen today leaves no room for forgiveness of the mentioned offences]
5:46 And after them We caused Jesus, son of Mary, to follow in their footsteps, confirming (the remaining truth in) what was revealed before him. We gave him the Gospel in which there was guidance and a light, and it confirmed the (truth in) what was revealed before it in the Torah, a guidance and admonition to those who wished to live upright. [2:101, 3:78]
5:47 Let the People of the Gospel judge by what God has revealed therein. And whoever fails to judge or rule by what God has revealed, are drifters from the right path (‘Fasiqoon’).