Book of Han: In extreme cold, with soldiers' fingers falling off, he was besieged for seven days by the Xiongnu at Pingcheng (the Baideng siege)…
In extreme cold, with soldiers' fingers falling off, he was besieged for seven days by the Xiongnu at Pingcheng (the Baideng siege); Chen Ping's secret plan enabled his escape.
遂至平城，為匈奴所圍，七日，用陳平祕計得出
Location: 漢書卷001 漢高祖七年十月
Gaozu set out to attack King Xin of Han and reached Pingcheng, but was besieged by the Xiongnu for seven days.
匈奴圍我平城，七日而後罷去。
Location: 史記卷008 高祖本紀