There is no third faction that says that the Messenger...
There is no third faction that says that the Messenger appointed a caliph for the Hashimites and left the rest of the Muslims without a caliph. The Holy Prophet would not make a clannish discrimination by appointing a caliph for his clan and leaving the rest of the Muslims without leadership. The Prophet by the nature of his message is supposed to be more concerned with the future of his nation than with the future of his clan.
Therefore it would be inconceivable that he appoints for his clan a religious authority that represents him and replaces him then leaves the millions of his followers without authority and leadership. Before I end my deliberation about this declaration I would like to dwell a little while upon the significance of the contents of this declaration.
The Final of the Prophets of God "brothered" a child of thirteen years and appointed him a "caliph" (successor) of his after that child gave the Prophet a promise that he will be his minister in his important mission. Let us first ask: What is the value of a promise of a child at this age to assist in such a tremendous mission which is concerned with the future of Islam and frought with great consequences of this kind?
Suppose a child of this age promises to assist you in realizing a considerably important project for the future. How can you rely on his promise? And what is the value of a promise of such a child whose opinion may change and his attitude could be reversed within days or hours? Again how could the Holy Prophet know the righteousness of ‘Ali and his capability of leadership in his future life while he is still thirteen years old?
The life of a child who seems to be good and righteous could change during his youth and manhood and his nature could become corrupt. It is also possible for a child who seems to be corrupt to change and become one of the best people during the days of his manhood. It is impossible for any human to know with certainty the future of a child. The knowledge of this belongs only to God who knows the future of everything.
The Holy Prophet's acceptance of ‘Ali's promised assistance in making the mission a success and the Prophet's taking that promise with such a high consideration shows that the Prophet had foreseen the bright future of ‘Ali with utmost certainty. Giving that child the high ranks of brotherhood executorship and successorship implies a clear prophecy concerning ‘Ali and his future superiority in knowledge righteousness bravery and wisdom.