Surah 9. Al-Tawba, Ayah 3

There is no unanimity among the commentators as to what is meant by "the day of the Greatest Pilgrimage". Most of them assume that it refers to the pilgrimage in the year 9 H., in which the Prophet himself did not participate, having entrusted Abu Bakr with the office of amir al-hajj. This very fact, however, makes it improbable that the designation "the Greatest Pilgrimage" should have been given in the Qur'an to this particular pilgrimage. On the other hand, there exists a Tradition on the authority of 'Abd Allah ibn 'Umar to the effect that the Prophet described in these very words the last pilgrimage led by himself in 10 H. and known to history as the Farewell Pilgrimage (Zamakhshari, Razi); one may, therefore, assume that it is this which is alluded to here. If this assumption is correct, it would justify the conclusion that verses {3} and {4} of this surah were revealed during the Farewell Pilgrimage, i.e., shortly before the Prophet's death. This might explain the - otherwise perplexing - statement, reliably attributed to the Prophet's Companion Al-Bara' (Bukhari, Kitab at-Tafsir), that At-Tawbah was the last surah revealed to the Prophet: for, although it is established beyond any doubt that the surah as a whole was revealed in 9 H. and was followed by several other parts of the Qur'an, e.g., Al-Ma'idah, it is possible that what Al-Bara' had in mind were only these two key-verses ({3} and {4}) of At-Tawbah, which conceivably were revealed during the Farewell Pilgrimage.

 The 10 th  of Ⱬul-Ḥijjah, a significant day in the greater pilgrimage (ḥajj). The lesser pilgrimage is known as ’umrah.

The great day of Hajj is either the 9th of Zul-hijjah ('Arafa), or the 10th (the Day of Sacrifice).