Ante-Nicene Fathers, Vol I:
POLYCARP: Chapter XIII.—The funeral pile is...

p. 42

Chapter XIII.—The funeral pile is erected.

This, then, was carried into effect with greater speed than it was spoken, the multitudes immediately gathering together wood and fagots out of the shops and baths; the Jews especially, according to custom, eagerly assisting them in it. And when the funeral pile was ready, Polycarp, laying aside all his garments, and loosing his girdle, sought also to take off his sandals,—a thing he was not accustomed to do, inasmuch as every one of the faithful was always eager who should first touch his skin. For, on account of his holy life, 454 he was, even before his martyrdom, adorned 455 with every kind of good. Immediately then they surrounded him with those substances which had been prepared for the funeral pile. But when they were about also to fix him with nails, he said, “Leave me as I am; for He that giveth me strength to endure the fire, will also enable me, without your securing me by nails, to remain without moving in the pile.”

Footnotes

Literally, “good behaviour.”

Some think this implies that Polycarp’s skin was believed to possess a miraculous efficacy.