Imam Khomeini explains the matter through his thelogical works as following:
The Prophet (S), whose knowledge was derived from the Divine Revelation, and whose soul was so great that it could preponderate over the spirits of millions upon millions of human beings, who rejected all the practices and customs of the pagan Arabs, who shattered under his feet all the false creeds, abrogated all the scriptures, and the circle of prophethood achieved its completion in his noble existence; who was the ruler of the world and the hereafter, and who was the master of all the worlds, with the permission of God Almighty; yet his humility towards the creatures of God was more than of any other human being.