What is the nickname for Prophet Muhammad?

All perfect praise be to Allaah, The Lord of the Worlds.  I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

Prophet Muhammad, sallallaahu ‘alayhi wa sallam, was nicknamed ‘Abul-Qaasim’ after his eldest son Al-Qaasim, as was the habit of the Arabs. It is reported in the authentic Sunnah (Prophetic tradition) that the Prophet, sallallaahu ‘alayhi wa sallam, was nicknamed thus.

Moreover, it is reported in Saheeh Muslim and other books that Jaabir ibn ‘Abdullaah narrated that the Prophet, sallallaahu ‘alayhi wa sallam, said: “You may give many names but you must not take my (Kunyah) surname. In fact, I am Abul-Qaasim and judge among you.”

However, the scholars differed about this nickname on whether it is peculiar to him, sallallaahu ‘alayhi wa sallam, only and not to other Muslims, or not. This difference is because of the content of the above Hadeeth, and this is the opinion of the scholars who judge by apparent meanings.

Others, however, said that this nickname is not peculiar to him. An-Nawawi said, “The scholars that judge by apparent meanings say that it is not permissible for anybody at all to nickname himself or be nicknamed by Abul-Qaasim whether his name is Muhammad or Ahmad or else, according to the meaning of the Hadeeth. The other opinion is that this prohibition is abrogated. This ruling was at the beginning, then it was abrogated. They said that in today's times it is permissible for everyone to be nicknamed Abul-Qaasim whether his name is Muhammad or Ahmad or other. This is the opinion of the Maaliki school of thought, and it is also the opinion of the majority of scholars.”

Allaah Knows best.