“Simon built up the strongholds of Judea. He walled them all around, with high towers and great walls, gates, and bolts. He stored food in the strongholds. Simon also chose emissaries and sent them to King Demetrius the king with a request to grant relief to the country. All that Trypho did was to plunder.”
Simon decided to build up the strongholds of Judea. He built walls around them with towers and gates. He stored food in them. He also sent messengers to the deposed King Demetrius II because he said that all King Trypho did was plunder the country. I guess that he was pushing for King Demetrius II to regain the kingship of Syria now that the pretence of the young King Antiochus VI was gone.