What is the difference between a miracle and a pre-prophetic sign?

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 'alyhi wa sallam, is His slave and Messenger.

As we have stated previously, a miracle is a supernatural matter which occurs at the hands of a prophet with which Allaah The Almighty supports him. It serves to prove that he is truthful and leaves no room for people to argue thereafter.

The definition of a pre-prophetic sign is stated by the scholars in Al-Mu‘jam Al-Waseet as a supernatural event which occurs at the hands of a prophet before he is entrusted with the mission of prophethood.

This indicates that while a miracle is a supernatural matter with which Allaah The Almighty proves the truthfulness of a prophet after entrusting him with prophethood, a pre-prophetic sign is a supernatural event which occurs at the hands of a prophet before he is entrusted with prophethood.

Allaah Knows best.