Does the noble verse: "Say, 'If I go astray, I only go astray to my own loss; and if I am guided, it is by what my Lord reveals to me. Indeed, He is All-Hearing, Ever-Near,'" imply the possibility of the Prophet (peace be upon him) and his followers going astray?

The verse: (Say: "If I go astray, I go astray only to my own loss.") Saba/50, does not indicate the possibility of the Prophet (peace be upon him) going astray. Rather, it was revealed as a matter of fairness to the disputant and to open up room for contemplation. Its meaning is that if, for the sake of argument, he were to go astray, its effect and consequence would be on him alone, and far be it from him to do so. Tafsir al-Sa'di confirms that misguidance is confined to the self and does not extend to others. Conditioning something on a premise does not mean its occurrence or possibility, as this has come in the Qur'an as a hypothetical for impossible matters, as in His (Allah's) saying: (Or do they say, "He has invented it"? Say, "If I have invented it, then you have no power to protect me from Allah whatsoever.") Al-Ahqaf/8, and (Say: "If the Most Merciful had a son, then I would be the first of worshippers.") Az-Zukhruf/81. Thus, conditioning something on a premise does not indicate the possibility of the conditioned, but rather it may be impossible.