An Chongrong, in addition to considering a rebellion against Later Jin, was particularly hostile to Liao. Whenever Liao emissaries passed through Chengde, he would curse them and sometimes even kill them. In 940, he seized a Liao emissary, and then submitted an arrogantly-worded petition to Shi, demanding that he terminate his submissiveness to Liao and turn against Liao for its mistreatment of the Chinese people. Sang secretly pointed out to Shi that turning against Liao could not yield any benefit — and, in his evaluation of Emperor Taizong, referred to Emperor Taizong as being "more intelligent and brave than other people." Shi listened to Sang, and instead tried to persuade An against provocative behaviors against Liao. He also sent Yang Yanxun (楊彥詢) the military governor of Anguo Circuit (安國, headquartered in modern Xingtai, Hebei) as an emissary to Liao, to explain to Emperor Taizong, who was angry over An's killing of Liao emissaries, to explain that An's provocative behavior did not reflect a chance in Later Jin's overall submission.