What is meant by the superiority of the Prophet Muhammad, peace and blessings be upon him? Is it from Allah, or due to his deeds, struggles, and دعوت (call to Islam)? And is this superiority definitive or conjectural?

The superiority of the Prophet, peace be upon him, in the sight of Allah is definitive, and this is evidenced by proofs from the Quran and Sunnah. Among them is that his message is universal for all people, whereas prophets before him were sent specifically to their own communities. Also, his saying, "I am the master of the children of Adam on the Day of Resurrection." Among these proofs is his exclusive right to the Great Intercession. This superiority comes from Allah, for He chose him and sealed prophethood with him, granted him a magnificent character, and favored him with the generosity, courage, forbearance, and patience in inviting to Allah and striving in His cause, with which He endowed him.