This is among the ways of idolaters and disbelievers to impede the Quran

There are many ways of disbelievers and their striving hard to impede the religion of God: the religion of the pure monotheism and truth.

So the Quran was revealed to the Prophet, and he was ordered to convey it to people; and the idolaters did much work to resist and impede the word of the truth included in the Glorious Quran.

Then Abu Sufian the chief of the idolaters of Mecca met some Jews and asked them in this way:

[Abu Sufyan asked some Jews: "What do you think about Mohammed: is he insane or is he a scholar?"
They said: "He is only a scholar that studied [the Torah!]"

He said:" Is he more knowledgeable or are your scholars?"
They said: "Our scholars, particularly the priest Huyay son of Akhtab and Ka'ab son of Ashraf, are more knowledgeable."

He said: "Which is true: his religion or your religion?"
They said: "The true is our religion."

He said: "Is his Quran of his own accord, or is it a revelation from heaven?"
They said: "Had it been any revelation, it would have been revealed to us; for we are more worthy of the revelation than he is; and had it been any prophecy, it would have been within us."

Therefore, this aya was revealed:]

Quran 4: 51, which means:
{Haven't you [Mohammed] regarded those [Jews] who were given a portion of the [Heavenly] Book [: the Torah], [how] they believe a in the priest [: Huyay, the son of Akhtab] and the tyrant [: Ka'ab, the son of Ashraf], and [how] they say to the disbelievers b: "These [Jewish priests] are more rightly guided than those [Mohammed and his companions] who believe c."}
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a i.e. they believe in their scholars and blindly follow them, even though they are in error, and in spite of that they sanctify them, and in particular the priest Huyay, the son of Akhtab.

b Abu Sufyan and his companions, when these asked them: Which has more knowledge: Mohammed or your scholars? So they answered:

c and they have more knowledge than Mohammed and his companions have.

The interpretation is by Mohammed-Ali Hassan Al-Hilly.