Emperor Gaozu 's son and invited him to serve as a resident scholar at Li Shimin 's mansion .
Emperor Gaozu 's son is the major general Li Shimin the Prince of Qin became aware of Du 's talents .
Emperor Gaozu 's son , the major general Li Shimin the Prince of Qin became aware of Du 's talents , and invited him to serve as a resident scholar at Li Shimin 's mansion .