How can one reconcile the two noble verses that describe the knowledge of the People of the Book concerning the Prophet Muhammad (peace be upon him) and the Qur’an, where one indicates their knowledge of him as they know their own sons, while the other points to their suspicious doubt concerning him?

The interpretation of Allah's saying: ﴿Those to whom We gave the Scripture recognize him as they recognize their own sons. But indeed, a party of them conceal the truth while they know it,﴾ is that the People of the Scripture knew the Prophet, peace and blessings be upon him, or his prophethood, or the correctness of the Qibla, with certain knowledge, just as they knew their own sons. Then they concealed this truth despite their knowledge of it.

The interpretation of Allah's saying: ﴿And those to whom We gave the Scripture know that it is sent down from your Lord in truth,﴾ is that the scholars among the People of the Scripture knew that the Qur'an is true and sent down from Allah. However, this knowledge did not benefit them due to their disbelief in it and their denial of its command. The prophets had indeed given glad tidings of Muhammad, peace and blessings be upon him, and his attributes.

As for Allah's saying: ﴿And We certainly gave Moses the Scripture, but difference arose therein. And had it not been for a word that preceded from your Lord, it would have been judged between them. And indeed, they are in disquieting doubt concerning it,﴾ there are several interpretations: that the doubt was in their denial and their disagreement regarding the truth; or that the pronoun "it" refers back to the Torah; or that it refers back to the Qur'an and "they" refers back to the disbelievers of Quraysh. There is no contradiction between the verses.