The well-known difference between a Prophet and a Messenger is that a Messenger is one to whom a law is revealed and he is commanded to convey it, whilst a Prophet is one to whom a law is revealed but he is not commanded to convey it. But this distinction is not free of problems, because a Prophet is also commanded to call people, convey the Message and judge among the people.

Hence Shaykh al-Islam Ibn Taymiyah said: The correct view is that the Messenger is one who is sent to a disbelieving people, and the Prophet is one who is sent to a believing people with the sharee’ah of the Messenger who came before him, to teach them and judge between them, as Allaah says (interpretation of the meaning):

“Verily, We did send down the Tawraat (Torah) [to Moosa (Moses)], therein was guidance and light, by which the Prophets, who submitted themselves to Allaah’s Will, judged for the Jews” [al-Maa’idah 5:44]

So the Prophets of the Children of Israel judged by the Tawraat which Allaah had revealed to Moosa.

With regard to the aayah,

“but he is the Messenger of Allaah and the last (end) of the Prophets” [al-Ahzaab 33:40]