What is meant here is that anyone who wants to find out about religion from them should argue with them in a manner that is better, as this will be more effective. Allah says:

{Invite to the way of your Lord with wisdom and fair preaching...} (16:125)

that Abu Hurayrah, may Allah be pleased with him, said, “The People of the Book used to read the Tawrah in Hebrew and explain it in Arabic to the Muslims. The Messenger of Allah said:

«Do not believe the People of the Book and do not deny them. Say: "We believe in Allah and what has been revealed to us and what has been revealed to you. Our God and your God is One, and to Him we have submitted."»

This Hadith was narrated only by Al-Bukhari.
Al-Bukhari recorded that Ibn 'Abbas said: “How can you ask the People of the Book about anything, when your Book that was revealed to the Messenger of Allah is more recent, you read it pure and uncontaminated, it tells you that the People of the Book altered and changed the Book, that they write the Book with their own hands and then say, This is from Allah,' to purchace with it a small price? Should not the knowledge that you have, prevent you from asking them? No, by Allah, we have never seen any of them asking you about what was sent down to you.”

Al-Bukhari recorded that Humayd bin 'Abdur-Rahman heard Mu'awiyah talking to a group of Quraysh in Al-Madinah. He mentioned Ka'b Al-Ahbar, and said: “He was one of the most truthful of those who narrated from the People of the Book, even though we found that some of what he said might be lies.”

I say, this means that some of what he said could be classified linguistically as lies, but he did not intend to lie, because he was narrating from manuscripts which he thought were good, but they contained fabricated material, because they did not have people who were so conscientious in memorizing the Scriptures by heart as the people of this great Ummah.