The Response to Those Who Cast Doubt on the Hadiths of the Two Sahihs

Question:
I have heard people say that there are some inauthentic hadiths in the Sahihs of al-Bukhari and Muslim. We ask for a response to this doubt. May Allah reward you with good?

Answer:
This is incorrect. The Two Sahihs were accepted by the Muslim community, and these are their hadiths known for their authenticity, serving as proof, except for one hadith where some narrators made a mistake. They attributed it to the Prophet (peace and blessings be upon him), whereas it is actually the statement of Ka'b al-Ahbar, according to the most correct opinion of the hadith scholars. It is the hadith of Abu Hurayrah in Sahih Muslim: "That Allah created the world in seven days, the first of which was Saturday and the last was Friday." This is an error; rather, it was in six days, the first of which was Sunday. This is the preserved version, as indicated by the Great Qur'an, which states it was in six days.
This is one hadith in Sahih Muslim where some narrators made a mistake. They attributed it to the Prophet (peace and blessings be upon him), whereas it is from Abu Hurayrah, from Ka'b al-Ahbar, not from the Prophet (peace and blessings be upon him). And Ka'b al-Ahbar made a mistake in it, and he was a Tabi'i (one of the generation after the Companions).