You need a pair of tongs to make a pair of tongs. So, where did the first blacksmith get that first pair of tongs? HaKaddoshBaruchHu provided the necessary as part of creation. Problem solved. Note that this is in the same neighborhood as the list of other items that, more or less seriously, could not have come about in the normal course of things.
Ten things were created at twilight of Shabbat eve. These are: the
mouth of the earth [that swallowed Korach]; the mouth of [Miriam's]
well; the mouth of [Balaam's] ass; the rainbow; the manna; [Moses']
staff; the shamir; the writing, the inscription and the tablets [of
the Ten Commandments]. Some say also the burial place of Moses and the
ram of our father Abraham. And some say also the spirits of
destruction as well as the original tongs, for tongs are made with
The theological issue is how to account for a list of phenomena that don't fit into the orderly operations of the natural world. And then, at the end, we get, 'some also say', which is a definite weakening. Since it takes tongs to make tongs (if you don't think practically about wooden alternatives), the first pair of tongs is in the same category as the mouths. I tend to see this as a bit of rabbinic wit. The thinkers of Pirkei were, perhaps not entirely seriously, solving the problem of 'tongs all the way down.'
A more serious view of this comes from Be'er Avot:
Tongs, which are made with tongs – The tongs are a metaphor for the
human ability to invent. In truth, no invention is really new, for all
the raw material and creative thinking needed to develop new
technology was given to Man by G-d.
It's important that tongs start from G-d and not from people to make a point, perhaps theological, about ultimate origin of creativity.