Abbasids. Shah-Kazemi writes that some among the Ahl al-Hadith in the third-century (ninth-century) Baghdad denied the event, which al-Tabari attempted to refute in his nonextant al-Walaya, or his unfinished Kitab al-Fada'il. Links to the Qur'an In Shia and some Sunni sources, two verses of the Qur'an are associated with the Ghadir Khumm: verse 5:3, which announces the perfection of Islam, and verse 5:67, which urges Muhammad to fulfill his divine instructions. The latter is sometimes known as the Verse of Tabligh, linked to the Ghadir Khumm by the Sunni al-Suyuti () and al-Razi () and the Shia al-Qumi (), among others. The verse warns Muhammad, Verse 5:3 of the Qur'an, known as the Verse of Ikmal al-Din, is similarly linked to the Ghadir Khumm by the Sunni al-Tabari () and al-Baghdadi () and the Shia al-Tusi (), among others. In contrast, Ya'qubi and most Sunni commentators associate this verse with the Farewell Pilgrimage. This verse includes the passage: Other literary references The narrative of the Ghadir Khumm has also been preserved in the Arabic literature. The earliest instance, according to Veccia Vaglieri () and Jafri, is a disputed poem attributed to Hassan ibn Thabit (), who accompanied Muhammad during the pilgrimage. According to Jafri, this poem has been preserved by Shia and some Sunni sources. It includes the verse, "Stand up, O Ali, for I find only you to be an Imam and a guide after I [Muhammad] depart." In regards to its authenticity, Amir-Moezzi does not find the attribution problematic, while Jafri considers it highly improbable that these events would have passed unrecorded by Ibn Thabit, who was the "official poet-reporter of Muhammad." The Shia al-Kumayt ibn Zayd () is another early poet who composed verses on the same theme. Interpretation While the authenticity of the Ghadir Khumm is not contested, its interpretation is a source of controversy between Sunni and Shia. is a polysemous Arabic word, the meanings of which have varied in different periods and contexts. Before the Islamic era, the term originally applied to any form of tribal association. Later, the word was used in the Qur'an and the hadith literature with different meanings, including 'Lord', 'trustee', and 'helper'. In the context of the Ghadir Khumm, however, the interpretation of the word tends to be split along sectarian lines. Shia sources interpret this word as meaning 'leader', 'master', and 'patron', while Sunni accounts of this sermon