And when he was at deepest of the darkness, like as a robber shining and terrible to the tyrants of hell, they beheld him and began to demand and enquire: Who is he that is so strong, so terrible, so clear and so shining? The world, which is to us subject, sent to us never such one dead, ne he sent to us never such gifts into hell. Who is he then that is so constant that is entered into the furthest end of our parts, and he doubteth not only of our torments, but yet he hath unbound them of their bonds whom we held and kept? And they that were wont to wail and weep under our torments, assail us now by their health. And now not only they fear us, but now threaten and menace us. And they said to their prince: What prince art thou? All thy gladness is perished and all thy joys be converted into weepings. When thou hangedst him in the cross thou knewest not what damage thou shouldst suffer in hell.
From The Golden Legend, Jacobus de Voragine
A detail from Christ in Limbo, Hieronymous Bosch.
The full image is one of those truly terrifying medieval depictions.
Related: Brandon Vogt has an ancient Holy Saturday homily I printed out once years ago. So glad to see it online. Go read it and ponder.