After a refutation of beliefs held by Christians, specially those which ascribe Godhood to Jesus, alongwith the promise of reward for those who acknowledge the truth and punishment for those who insist on denying, the text turns to a universal address praising the blessed status and mission of His Messenger who taught what was the truth revealed to him, who conveyed the truth of the Qur'an admirably, and also those who believed in and testified to the truth of the Book and the Messenger.

What is Burhan?

The word, Burhan, appearing in verse قَدْ جَاءَكُم بُرْ‌هَانٌ مِّن رَّ‌بِّكُمْ proof has come to you from your Lord) lexically means proof refers to the Holy Prophet ﷺ . (Ruh al-Ma` ani)

Sayyidna Ibn ` Abbas ؓ says that the Holy Prophet ﷺ was referred to as 'Burhan' in consideration of his blessed person, his noble morals, his miracles and his being the very recipient of the revelation of the Book of Allah. All these are open proofs of his prophethood beyond which there remains no need for any other proof. Thus, in summation, his person is, in itself, proof personified.

As for the word, وَأَنزَلْنَا إِلَيْكُمْ نُورً‌ا مُّبِينًا (and We have sent down to you a vivid light) (174), it refers to the Holy Qur'an (Ruh al-Ma` ani) which also seems to be the case in Verse 15 of Surah al-Ma` idah (5): قَدْ جَاءَكُم مِّنَ اللَّـهِ نُورٌ‌ وَكِتَابٌ مُّبِينٌ (There has come to you from Allah a light and clear Book). In the explanatory translation of Maulana Ashraf Thanavi (رح) in Bayan al-Qur'an, the rendering of this verse appears as: 'There has come to you from Allah a light and (which is) a clear Book (that is) the Qur'an.' In this verse, what has been first identified as 'Nu-r' (light) has later been called 'kitabum-mubin' (clear Book). Let there be no doubt at this point that the conjunction demands dissimilarity, therefore, Nur (light) and Kitab (book) cannot be one and the same thing. The answer is that dissimilarity in expression is sufficient, even though the meanings are the same. (Ruh al-Ma` ani)

And if 'Nur' (light) is taken as referring to the Holy Prophet ﷺ and 'Kitab' (the Book) to the Holy Qur'an - that will also be correct (Ruh al-Ma` ani). But, this does not go on to prove that the Holy Prophet ﷺ was Nur or light in the literal sense, therefore, it is not against his being physically human.