During this time, remembering Gao Xiaoji's kindness toward him, he commissioned a stone tablet monument for Gao. Around the new year of 630, however, Du resigned due to illness.
As he reflected on Gao Xiaoji's generosity towards him, he decided to erect a stone tablet monument in honor of Gao. Unfortunately, Du relinquished his position around the beginning of 630, owing to health reasons.