sentences:  Fang and Du, initially fearing Emperor Gaozu's orders forbidding them to serve Li Shimin, declined.In anger, Li Shimin sent the general Yuchi Gong to summon Fang and Du, with directions that if they declined again, to kill them.Yuchi, however, was able to persuade them that Li Shimin was in fact intending on acting against Li Jiancheng and Li Yuanji, and so Fang and Du put on disguises as Taoist monks and were able to get to Li Shimin's mansions, where they assisted Li Shimin in planning the ambush against Li Jiancheng and Li Yuanji.