Does Surah Al-Anfal, Ayah 43 mean that Allah showed the Prophet (peace be upon him) a number of polytheists that was contrary to reality, and then the Prophet (peace be upon him) informed the Companions of something contrary to the truth? And how can this occur when Allah is free from imperfection and the Messenger is infallible?

Most scholars are of the view that the verse: ﴿إِذْ يُرِيكَهُمُ اللَّهُ فِي مَنَامِكَ قَلِيلًا وَلَوْ أَرَاكَهُمْ كَثِيرًا لَفَشِلْتُمْ وَلَتَنَازَعْتُمْ فِي الْأَمْرِ وَلَكِنَّ اللَّهَ سَلَّمَ إِنَّهُ عَلِيمٌ بِذَاتِ الصُّدُورِ﴾ (Al-Anfal: 43) refers to a dream vision. The meaning is that Allah showed the Prophet the polytheists as few in his dream to strengthen the hearts of the believers and encourage them to fight their enemy. Had He shown them the large number of their enemy, they would have become cowardly and disputed among themselves.

Ibn Kathir found it strange to say that "in your dream" means "in your eye," due to the lack of evidence for it.

Scholars believe that this vision was a wisdom from Allah, as the Prophet informed the Muslims about it, which encouraged them and was a reason for victory. The small number in the vision was a metaphor for the weakness and humiliation of the polytheists, not for their actual small number.

In summary, the vision was a dream and explicitly mentioned in the Quran, and it was a metaphor for the weakness and humiliation of the polytheists, which strengthened the hearts of the believers and contributed to their victory.