The word: bayyinah (بینہ) appearing in this verse refers to the Qur'an. As for the meaning of ` shahid' (شاھِد evidence), statements of Tafsir authorities differ. The author of Bay-an a1-Qur'an takes ` shahid' to mean the miracle of the Qur'an that is present in the Qur'an as such. Thus, it comes to mean that those who adhere to the Qur'an, they already have a witness to the veracity of the Qur'an within it, that is, its miracle. Then, the other witness has already come in the form of Torah. Sayyidna Musa (علیہ السلام) had brought it as guidance and mercy for people. The reason is that the Torah confirms the truth of the Qur'an clearly.
In the second sentence, in order to stress that salvation, up to the Last Day, depends on faith in the Holy Prophet ﷺ it has been said that anyone from any religion or community of the world who refuses to have faith in him will have his abode in Jahannam.
The Sahih of Muslim reports on the authority of Sayyidna Abu Hurairah ؓ that the Holy Prophet ﷺ said, ` by the One in whose hands rests my life, any Jew or Christian who hears my call and still does not believe in the teachings I have brought, then, he or she will be of the people of Jahannam.'
This should remove the misunderstanding of those who regard the Jews and Christians or the adherents of other religions as being on haqq (the truth) on the basis of some outward deeds and consider these to be sufficient for salvation without having faith in the Holy Prophet ﷺ and the Qur'an. This is an open clash with the present ayah of the Holy Qur'an, and the authentic ahadith. اَلعَیَاذ بِاللہ (Allah may save us from that! )