Atalanta Fugiens · 1618 · Emblem XXXV
Ut Ceres Triptolemum, Thetis Achillem, sub igne morari assuefecit, sic artifex lapidem.
As Ceres accustomed Triptolemus, and Thetis Achilles, to stay in the fire, so the artist [accustoms] the stone.
In the myths, the goddesses held the children in fire to make them strong. The stone is accustomed to heat slowly, not thrown into it.
What are you slowly getting used to that will make you stronger?
Michael Maier, Atalanta Fugiens (Oppenheim, 1618). Engraving in the public domain. Motto transcribed from the 1618 edition; translation and reading by The Hermetic School. All the emblems.