Wei Zheng
In 634, Emperor Taizong sent 13 high level officials, including Li Jing and Xiao Yu, to examine the circuits to see whether the local officials were capable, to find out whether the people were suffering, to comfort the poor, and to select capable people to serve in civil service. (Li Jing initially recommended Wei Zheng, but Emperor Taizong declined sending Wei, stating that Wei needed to stay to point out his faults and that he could not afford to have Wei away even for a single day.)