Ambrose of Milan

But it must also be explained how the others, that is, Matthew and Mark, introduced two thieves reviling, while Luke, one reviling, the other resisting him. Perhaps this other at first reviled, but was suddenly converted. It may also have been spoken of one, but in the plural number; as in the Hebrews, They wandered in goat-skins, and they were sawn asunder; (Heb. 11:37.) whereas Elijah alone is related to have had a goat-skin, and Isaiah to have been sawn asunder. But mystically, the two thieves represent the two sinful people who were to be crucified by baptism with Christ, (Rom. 6:3.) whose disagreement likewise represents the difference of believers.