التفسير التبليغي
(Say, "O People of the Scripture, why do you disbelieve in the verses of Allah, while Allah is a Witness over what you do?") (98)
This is a reprimand, a denunciation, a condemnation, and a warning against their stubborn rejection of the truth, their disbelief in the signs of Allah, and their hindering from His path anyone among the people of faith who desires it.
(Say, "O People of the Scripture...") : The apparent address is to the People of the Scripture, but its inner meaning is a message to the evil scholars who pursue worldly gains through religion and what they do.
It is an insult to them for their obstruction of the truth.
(why do you disbelieve in the verses of Allah) : Meaning, in what the Qur'an brought forth as an effort for the religion.
The verses (Ayat): These are the signs that Allah has established as an indication of the truth.
He, glorified be He, threatens them with what would tear hearts apart.
(while Allah is a Witness over what you do) : Meaning, nothing of what you do is hidden from Him, and He will recompense you for it.
(while Allah is a Witness over what you do) : He – glorified be He – knows the secret and what is even more hidden, even if you distort and conceal.
The Witness (Ash-Shahid): The One Who is aware of everything, Whose knowledge encompasses everything, the One Who bears witness against His servants regarding what they have done.
Source: التفسير التبليغي