At Hadid he blocked the advance of the Seleucid general, Diodotus Tryphon, who was attempting to enter the country and seize the throne of Syria. Since Tryphon could gain nothing by force, he demanded a ransom for Jonathan and the surrender of Jonathan's sons as hostages. Although Simon was fully aware that Tryphon would deceive him, he acceded to both demands, so that the people might see that he had done everything possible for his brother.