Dhu Nuwas
Ibn Ishaq-Guillaume interpreted this passage to be an allusion to the killing of the Christians of Najran by order of the King Dhu Nuwas. According to Christian sources, this event took place around 523 C.E. Dhu Nuwas converted to Judaism and chose Joseph as his new name. He went to Najran to force the Christian people there to convert to Judaism. When they refused, the King threw them alive into one or more burning ditches.