How do we respond to the specious argument that some Companions accused others of apostasy, citing Al-Dhahabi's statement in "Mizan al-I'tidal": "Some Companions indeed declared others to be disbelievers, and if a Muslim says to his brother, 'O disbeliever,' then one of them has certainly deserved it"?

Al-Dhahabi said that some Companions declared others to be disbelievers based on an interpretation [ta’wil], yet Allah is pleased with all of them and forgives them, for they are not infallible. Their disagreements and battles do not diminish their standing with us. Their narrations were weakened by the Khawarij declaring them disbelievers; rather, the words of the Khawarij and the Shi'a against them became a criticism of those who slandered them.

As for the Companions, their matter is settled, regardless of what transpired. Even if they erred, like other trustworthy narrators, their errors are rare and never detrimental, for their integrity and the acceptance of what they narrated are the basis of our practice, and by it, we worship Allah the Almighty.

Therefore, what occurred from some of the Companions does not undermine their integrity or their Islam, because it happened due to an interpretation. There is no explicit text stating that some Companions declared others disbelievers. Rather, some were accused of hypocrisy, as in the story of Hatib ibn Abi Balta'ah, but this occurred due to an interpretation, and thus it does not necessitate the disbelief of the speaker or the one spoken about.