After the arrival of this verse the Noble Prophet understood...
After the arrival of this verse the Noble Prophet understood that he should hasten with this responsibility and deliver this message as soon as the opportunity arose, and hence the afore mentioned event took place at Ghadīr Khum. The aim of this event was to officially announce the successor of the Prophet and gain public allegiance.
However through the course of time the succession of Ali had been mentioned on various occasions: At the beginning of the advent of Islam, when the Prophet was ordered to proclaim his message publicly, he was first told to warn those nearest to him. He invited his family members to a meeting and said that the first to accept his message would be his successor. All Muslims agree that Ali was the first to accept Islam.
Likewise, when the following verse was revealed, the obedience to those with authority (ūlī-l-amr) had been made absolutely obligatory and the obedience of those with the authority is regarded to be at the same level as obedience to the Prophet (s): “O you who have faith!
Obey Allah and obey the Apostle and those vested with authority among you.” (al-Nisā’:59) Jaber ibn Abdullah al-Ansari asked the Prophet about those with authority, who replied: “The First of them is Ali ibn Abi Talib, then al Hssan, then al Husayn ibn Ali, then Ali ibn al Husayn, then Mohammed ibn Ali, known as Baqir in the Torah -You will see him O Jaber, so give my Salams to him - then Jafer al Sadiq ibn Mohammed, then Musa ibn Jafer, then Ali ibn Musa, then Mohammed ibn Ali, then Ali ibn Mohammed, then Hassan ibn Ali, and then the one whose title is Hujjat Allah (Evidence of God) upon this earth….” The prophesy of the Prophet came true, Jaber was alive till the period of Imam al Baqir (a) and he delivered the Prophet’s salutations to the fifth successor.
In another tradition Abu Basir narrates with reference to the verse of authority, from Imam al Sadiq (a), that this verse was revealed in the honour of Ali ibn Abi Talib, Hasan and Husayn (a). Abu Basir asked the Imam how to answer people who argued as to why Ali (a) and the Prophet’s household were not mentioned in the Qur’an by name.
Imam Sadiq (a) told him to: “Tell them that, the verses revealed with reference to the prayers, did not mention any names for the three and four rak’ah prayers, this was indeed relayed to the people by the Prophet”. Likewise the Prophet explained the verses of alms (zakāh) and pilgrimage (hajj), and therefore he must also interpret the verse of authority.