"
And from the flames
As chance would have it
The soulforged will come into light
And from the flames
As chance would have it
The soulforged, the stainless will rise
As mentioned before Raistlin had to take a test in order to become a wizard, described in a book called "The Soulforge". During this test, his soul was supposed to be "forged" in the flames of the magic to ensure his dedication.