I understand that it is narrated in Al-Kafi that the Quranic verse 5:3 was revealed on the day of Arafah. This contradicts the view of it being revealed after the Ghadeer sermon. How can this narration be explained?
This narration is weak and not authentic because of its narrator (Jafar al-Khuza'ee) is unknown and never been authenticated by any of our Ulama. Al-Majlisi in Baharul Anwaar mentioned that this narration is weak.
Al-Kho'ee in Mo'jam Rijal al-Hadeeth stated that the narrator ( Jafar Al-Khzaa'ee is unknown.
'The authentic narrations in all Shia books and many Sunni books stated that this verse was revealed on the Day of Ghadeer. (Al-Kafi 1:289, and 1:198)
Many Sunni scholars narrated authentic Hadeeths that this verse was revealed on the Day of Ghadeer e.g.
1.Al-Tabari in his book Al-Wilayah,
2, Ibn Oqdah.
3. Ibn Asaakir.
4. Ibn Mardawayh.
5. Al-Hafidh Abu Na'eem in his book (Maha Nazala Min al-Quran Fi Ali).
6. Al-Khateeb al-Baghdadi in Tareekh Baghdad 8:290 .
7.al-Hafidh al-Sijistani in his book al-Wikayah.
8. Al-Khawarizmi in al-Manaaqib:page 80.
9. al-Hamaweeni al-Hanafi in Faraa'id al-Simtayn in chapter 12.
No scholar can turn his face away from many authentic narrations and take instead a single weak narration.
Wassalam