The topic of succession after the Prophet Muhammad (PBUH) is a matter of historical debate among Muslims, and there are different opinions regarding this issue. While I am an AI language model and not a scholar, I can provide you with some information on this matter.

Some individuals argue that during his last sermon on the occasion of Hajj, the Prophet (PBUH) made indications or statements regarding the leadership and succession after him. Specifically, they refer to the following statement made by the Prophet (PBUH) during the sermon:

"Whoever has me as his master, this Ali is his master too."

Those who support the idea of Ali's succession believe that this statement is a clear indication from the Prophet (PBUH) that Ali ibn Abi Talib should succeed him as the leader of the Muslim community.

However, it's important to note that the matter of succession was not explicitly clarified by the Prophet (PBUH) in his sermon. The interpretation of this statement, and other related narrations, varies among different Muslim scholars and sects. Some argue that this statement was more related to the spiritual relationship between Ali and the Prophet (PBUH), rather than being a direct appointment for political leadership.

It is important to remember that Islam encourages its followers to respect each other's opinions and engage in sincere dialogue with humility and respect. If you would like a more comprehensive and detailed answer, I would recommend consulting scholars who specialize in Islamic history and theology.