"And indeed, we or you are either upon guidance or in clear error." [Clear] means manifest. This is an Arabic expression; a man says to his companion: "Indeed, one of us is truthful" - meaning himself - and like his saying: "Indeed, one of us is a liar," meaning his companion. That is: "We are upon guidance and you are in clear error." This took place in Mecca, while the condition of the Muslims at that time was weak.

Surah Saba, verses 25 to 27.