Once some Christians came to Imam (a.s) and said, “Prophet Musa, Isa and Muhammad are equal in rank, because each of them got one book and one Shariat (Divine Law). Imam (a.s) said, Prophet Muhammad was higher to them in rank due to the knowledge and superiority Allah had given him exclusively. The Christians asked this to be proved by a verse of Quran. Imam (a.s) said, “It is mentioned regarding Prophet Musa:
And We ordained for him in the tablets admonition of every kind and clear explanation of all things; (Surah Araaf 7:145)
And regarding Isa (a.s) He says,
I have come to you indeed with wisdom, and that I may make clear to you part of what you differ in;(Surah Zukhruf 43:63)
Regarding the Messenger of Allah (S), it says,
…and We have revealed the Book to you explaining clearly everything… (Surah Nahl 16:89)
Reference :Akhlaq al-A’imma, Morals & Manners of the Holy Imams